Index: src/ajax.c
==================================================================
--- src/ajax.c
+++ src/ajax.c
@@ -264,16 +264,18 @@
   }
   return rc;
 }
 
 /*
-** AJAX route /ajax/preview-wiki
+** AJAX route /ajax/preview-text
 **
 ** Required query parameters:
 **
 ** filename=name of content, for use in determining the
-** mimetype/render mode.  content=text
+** mimetype/render mode.
+**
+** content=text
 **
 ** Optional query parameters:
 **
 ** render_mode=integer (AJAX_RENDER_xxx) (default=AJAX_RENDER_GUESS)
 **
@@ -365,11 +367,11 @@
   const AjaxRoute * rB = (const AjaxRoute*)b;
   return fossil_strcmp(rA->zName, rB->zName);
 }
 
 /*
-** WEBPAGE: ajax
+** WEBPAGE: ajax hidden
 **
 ** The main dispatcher for shared ajax-served routes. Requires the
 ** 'name' parameter be the main route's name (as defined in a list in
 ** this function), noting that fossil automatically assigns all path
 ** parts after "ajax" to "name", e.g. /ajax/foo/bar assigns

Index: src/chat.c
==================================================================
--- src/chat.c
+++ src/chat.c
@@ -125,11 +125,11 @@
 */
 /*
 ** SETTING: chat-alert-sound     width=10
 **
 ** This is the name of the builtin sound file to use for the alert tone.
-** The value must be the name of one of a builtin WAV file.
+** The value must be the name of a builtin WAV file.
 */
 /*
 ** WEBPAGE: chat
 **
 ** Start up a browser-based chat session.
@@ -154,19 +154,25 @@
   zProjectName = db_get("project-name","Unnamed project");
   style_set_current_feature("chat");
   style_header("Chat");
   @ <form accept-encoding="utf-8" id="chat-form" autocomplete="off">
   @ <div id='chat-input-area'>
-  @   <div id='chat-input-line'>
+  @   <div id='chat-input-line' class='single-line'>
   @     <input type="text" name="msg" id="chat-input-single" \
-  @      placeholder="Type message for %h(zProjectName)." autocomplete="off">
+  @      placeholder="Type markdown-formatted message for %h(zProjectName)." \
+  @      autocomplete="off">
   @     <textarea rows="8" id="chat-input-multi" \
-  @      placeholder="Type message for %h(zProjectName). Ctrl-Enter sends it." \
+  @      placeholder="Type markdown-formatted message for %h(zProjectName). Ctrl-Enter sends it." \
   @      class="hidden"></textarea>
-  @     <input type="submit" value="Send" id="chat-message-submit">
-  @     <span id="chat-settings-button" class="settings-icon" \
-  @       aria-label="Settings..." aria-haspopup="true" ></span>
+  @     <div id='chat-edit-buttons'>
+  @       <button id="chat-preview-button" \
+  @         title="Preview message">&#128065;</button>
+  @       <button id="chat-settings-button" \
+  @         title="Configure chat">&#9881;</button>
+  @       <button id="chat-message-submit" \
+  @         title="Send message">&#128228;</button>
+  @     </div>
   @   </div>
   @   <div id='chat-input-file-area'>
   @     <div class='file-selection-wrapper'>
   @       <div class='help-buttonlet'>
   @        Select a file to upload, drag/drop a file into this spot,
@@ -177,21 +183,27 @@
   @     </div>
   @     <div id="chat-drop-details"></div>
   @   </div>
   @ </div>
   @ </form>
+  @ <div id='chat-preview' class='hidden'>
+  @  <header>Preview:</header>
+  @  <div id='chat-preview-content' class='message-widget-content'></div>
+  @  <div id='chat-preview-buttons'><button id='chat-preview-close'>Close Preview</button></div>
+  @ </div>
   @ <div id='chat-config' class='hidden'>
   @ <div id='chat-config-options'></div>
     /* ^^^populated client-side */
-  @ <button>Close</button>
+  @ <button>Close Settings</button>
   @ </div>
   @ <div id='chat-messages-wrapper'>
   /* New chat messages get inserted immediately after this element */
   @ <span id='message-inject-point'></span>
   @ </div>
   fossil_free(zProjectName);
-  builtin_fossil_js_bundle_or("popupwidget", "storage", "fetch", NULL);
+  builtin_fossil_js_bundle_or("popupwidget", "storage",
+                              "fetch", "pikchr", NULL);
   /* Always in-line the javascript for the chat page */
   @ <script nonce="%h(style_nonce())">/* chat.c:%d(__LINE__) */
   /* We need an onload handler to ensure that window.fossil is
      initialized before the chat init code runs. */
   @ window.addEventListener('load', function(){
@@ -201,10 +213,11 @@
   @   fromcli: %h(PB("cli")?"true":"false"),
   @   alertSound: "%h(zAlert)",
   @   initSize: %d(db_get_int("chat-initial-history",50)),
   @   imagesInline: !!%d(db_get_boolean("chat-inline-images",1))
   @ };
+  ajax_emit_js_preview_modes(0);
   chat_emit_alert_list();
   cgi_append_content(builtin_text("chat.js"),-1);
   @ }, false);
   @ </script>
 
@@ -294,11 +307,11 @@
   }
   fossil_free(zTime);
 }
 
 /*
-** WEBPAGE: chat-send
+** WEBPAGE: chat-send hidden
 **
 ** This page receives (via XHR) a new chat-message and/or a new file
 ** to be entered into the chat history.
 **
 ** On success it responds with an empty response: the new message
@@ -347,79 +360,25 @@
   db_commit_transaction();
 }
 
 /*
 ** This routine receives raw (user-entered) message text and transforms
-** it into HTML that is safe to insert using innerHTML.
-**
-**    *   HTML in the original text is escaped.
-**
-**    *   Hyperlinks are identified and tagged.  Hyperlinks are:
-**
-**          -  Undelimited text of the form https:... or http:...
-**          -  Any text enclosed within [...]
+** it into HTML that is safe to insert using innerHTML. As of 2021-09-19,
+** it does so by using markdown_to_html() to convert markdown-formatted
+** zMsg to HTML.
 **
 ** Space to hold the returned string is obtained from fossil_malloc()
 ** and must be freed by the caller.
 */
 static char *chat_format_to_html(const char *zMsg){
-  char *zSafe = mprintf("%h", zMsg);
-  int i, j, k;
   Blob out;
-  char zClose[20];
-  blob_init(&out, 0, 0);
-  for(i=j=0; zSafe[i]; i++){
-    if( zSafe[i]=='[' ){
-      for(k=i+1; zSafe[k] && zSafe[k]!=']'; k++){}
-      if( zSafe[k]==']' ){
-        zSafe[k] = 0;
-        if( j<i ){
-          blob_append(&out, zSafe + j, i-j);
-          j = i;
-        }
-        blob_append_char(&out, '[');
-        wiki_resolve_hyperlink(&out,
-                               WIKI_NOBADLINKS|WIKI_TARGET_BLANK|WIKI_NOBRACKET,
-                               zSafe+i+1, zClose, sizeof(zClose), zSafe, 0);
-        zSafe[k] = ']';
-        j++;
-        blob_append(&out, zSafe + j, k - j);
-        blob_append(&out, zClose, -1);
-        blob_append_char(&out, ']');
-        i = k;
-        j = k+1;
-        continue;
-      }
-    }else if( zSafe[i]=='h' 
-           && (strncmp(zSafe+i,"http:",5)==0
-               || strncmp(zSafe+i,"https:",6)==0) ){
-      for(k=i+1; zSafe[k] && !fossil_isspace(zSafe[k]); k++){}
-      if( k>i+7 ){
-        char c = zSafe[k];
-        if( !fossil_isalnum(zSafe[k-1]) && zSafe[k-1]!='/' ){
-          k--;
-          c = zSafe[k];
-        }
-        if( j<i ){
-          blob_append(&out, zSafe + j, i-j);
-          j = i;
-        }
-        zSafe[k] = 0;        
-        wiki_resolve_hyperlink(&out, WIKI_NOBADLINKS|WIKI_TARGET_BLANK,
-                               zSafe+i, zClose, sizeof(zClose), zSafe, 0);
-        zSafe[k] = c;
-        blob_append(&out, zSafe + j, k - j);
-        blob_append(&out, zClose, -1);
-        i = j = k;
-        continue;
-      }
-    }
-  }
-  if( j<i ){
-    blob_append(&out, zSafe+j, j-i);
-  }
-  fossil_free(zSafe);
+  blob_init(&out, "", 0);
+  if(*zMsg){
+    Blob bIn;
+    blob_init(&bIn, zMsg, (int)strlen(zMsg));
+    markdown_to_html(&bIn, NULL, &out);
+  }
   return blob_str(&out);
 }
 
 /*
 ** COMMAND: test-chat-formatter
@@ -442,11 +401,11 @@
     fossil_free(zOut);
   }
 }
 
 /*
-** WEBPAGE: chat-poll
+** WEBPAGE: chat-poll hidden
 **
 ** The chat page generated by /chat using an XHR to this page to
 ** request new chat content.  A typical invocation is:
 **
 **     /chat-poll/N
@@ -651,11 +610,88 @@
   cgi_set_content(&json);
   return;      
 }
 
 /*
-** WEBPAGE: chat-download
+** WEBPAGE: chat-fetch-one hidden
+**
+** /chat-fetch-one/N
+**
+** Fetches a single message with the given ID, if available.
+**
+** Options:
+**
+**   raw = the xmsg field will be returned unparsed.
+**
+** Response is either a single object in the format returned by
+** /chat-poll (without the wrapper array) or a JSON-format error
+** response, as documented for ajax_route_error().
+*/
+void chat_fetch_one(void){
+  Blob json = empty_blob;   /* The json to be constructed and returned */
+  const int fRaw = PD("raw",0)!=0;
+  const int msgid = atoi(PD("name","0"));
+  Stmt q;
+  login_check_credentials();
+  if( !g.perm.Chat ) {
+    chat_emit_permissions_error(0);
+    return;
+  }
+  chat_create_tables();
+  cgi_set_content_type("application/json");
+  db_prepare(&q, 
+    "SELECT datetime(mtime), xfrom, xmsg, length(file),"
+    "       fname, fmime, lmtime"
+    "  FROM chat WHERE msgid=%d AND mdel IS NULL",
+    msgid);
+  if(SQLITE_ROW==db_step(&q)){
+    const char *zDate = db_column_text(&q, 0);
+    const char *zFrom = db_column_text(&q, 1);
+    const char *zRawMsg = db_column_text(&q, 2);
+    const int nByte = db_column_int(&q, 3);
+    const char *zFName = db_column_text(&q, 4);
+    const char *zFMime = db_column_text(&q, 5);
+    const char *zLMtime = db_column_text(&q, 7);
+    blob_appendf(&json,"{\"msgid\": %d,", msgid);
+
+    blob_appendf(&json, "\"mtime\":\"%.10sT%sZ\",", zDate, zDate+11);
+    if( zLMtime && zLMtime[0] ){
+      blob_appendf(&json, "\"lmtime\":%!j,", zLMtime);
+    }
+    blob_append(&json, "\"xfrom\":", -1);
+    if(zFrom){
+      blob_appendf(&json, "%!j,", zFrom);
+    }else{
+      /* see https://fossil-scm.org/forum/forumpost/e0be0eeb4c */
+      blob_appendf(&json, "null,");
+    }
+    blob_appendf(&json, "\"uclr\":%!j,",
+                 user_color(zFrom ? zFrom : "nobody"));
+    blob_append(&json,"\"xmsg\":", 7);
+    if(fRaw){
+      blob_appendf(&json, "%!j,", zRawMsg);
+    }else{
+      char * zMsg = chat_format_to_html(zRawMsg ? zRawMsg : "");
+      blob_appendf(&json, "%!j,", zMsg);
+      fossil_free(zMsg);
+    }
+    if( nByte==0 ){
+      blob_appendf(&json, "\"fsize\":0");
+    }else{
+      blob_appendf(&json, "\"fsize\":%d,\"fname\":%!j,\"fmime\":%!j",
+                   nByte, zFName, zFMime);
+    }    
+    blob_append(&json,"}",1);
+    cgi_set_content(&json);
+  }else{
+    ajax_route_error(404,"Chat message #%d not found.", msgid);
+  }
+  db_finalize(&q);
+}
+
+/*
+** WEBPAGE: chat-download hidden
 **
 ** Download the CHAT.FILE attachment associated with a single chat
 ** entry.  The "name" query parameter begins with an integer that
 ** identifies the particular chat message. The integer may be followed
 ** by a / and a filename, which will indicate to the browser to use
@@ -684,11 +720,11 @@
   cgi_set_content(&r);
 }
 
 
 /*
-** WEBPAGE: chat-delete
+** WEBPAGE: chat-delete hidden
 **
 ** Delete the chat entry identified by the name query parameter.
 ** Invoking fetch("chat-delete/"+msgid) from javascript in the client
 ** will delete a chat entry from the CHAT table.
 **

Index: src/chat.js
==================================================================
--- src/chat.js
+++ src/chat.js
@@ -101,20 +101,24 @@
       e:{/*map of certain DOM elements.*/
         messageInjectPoint: E1('#message-inject-point'),
         pageTitle: E1('head title'),
         loadOlderToolbar: undefined /* the load-posts toolbar (dynamically created) */,
         inputWrapper: E1("#chat-input-area"),
+        inputLine: E1('#chat-input-line'),
         fileSelectWrapper: E1('#chat-input-file-area'),
         messagesWrapper: E1('#chat-messages-wrapper'),
         inputForm: E1('#chat-form'),
         btnSubmit: E1('#chat-message-submit'),
         inputSingle: E1('#chat-input-single'),
         inputMulti: E1('#chat-input-multi'),
         inputCurrent: undefined/*one of inputSingle or inputMulti*/,
         inputFile: E1('#chat-input-file'),
         contentDiv: E1('div.content'),
-        configArea: E1('#chat-config')
+        configArea: E1('#chat-config'),
+        previewArea: E1('#chat-preview'),
+        previewContent: E1('#chat-preview-content'),
+        btnPreview: E1('#chat-preview-button')
       },
       me: F.user.name,
       mxMsg: F.config.chat.initSize ? -F.config.chat.initSize : -50,
       mnMsg: undefined/*lowest message ID we've seen so far (for history loading)*/,
       pageIsActive: 'visible'===document.visibilityState,
@@ -147,12 +151,14 @@
       /** Toggles between single- and multi-line edit modes. Returns this. */
       inputToggleSingleMulti: function(){
         const old = this.e.inputCurrent;
         if(this.e.inputCurrent === this.e.inputSingle){
           this.e.inputCurrent = this.e.inputMulti;
+          this.e.inputLine.classList.remove('single-line');
         }else{
           this.e.inputCurrent = this.e.inputSingle;
+          this.e.inputLine.classList.add('single-line');
         }
         const m = this.e.messagesWrapper,
               sTop = m.scrollTop,
               mh1 = m.clientHeight;
         D.addClass(old, 'hidden');
@@ -485,10 +491,67 @@
         F.toast.message("Deleted message "+id+".");
       }
       return !!e;
     };
 
+    /**
+       Toggles the given message between its parsed and plain-text
+       representations. It requires a server round-trip to collect the
+       plain-text form but caches it for subsequent toggles.
+
+       Expects the ID of a currently-loaded message or a
+       message-widget DOM elment from which it can extract an id.
+       This is an aync operation the first time it's passed a given
+       message and synchronous on subsequent calls for that
+       message. It is a no-op if id does not resolve to a loaded
+       message.
+    */
+    cs.toggleTextMode = function(id){
+      var e;
+      if(id instanceof HTMLElement){
+        e = id;
+        id = e.dataset.msgid;
+      }else{
+        e = this.getMessageElemById(id);
+      }
+      if(!e || !id) return false;
+      else if(e.$isToggling) return;
+      e.$isToggling = true;
+      const content = e.querySelector('.message-widget-content');
+      if(!content.$elems){
+        content.$elems = [
+          content.firstElementChild, // parsed elem
+          undefined // plaintext elem
+        ];
+      }else if(content.$elems[1]){
+        // We have both content types. Simply toggle them.
+        const child = (
+          content.firstElementChild===content.$elems[0]
+            ? content.$elems[1]
+            : content.$elems[0]
+        );
+        delete e.$isToggling;
+        D.append(D.clearElement(content), child);
+        return;
+      }
+      // We need to fetch the plain-text version...
+      const self = this;
+      F.fetch('chat-fetch-one',{
+        urlParams:{ name: id, raw: true},
+        responseType: 'json',
+        onload: function(msg){
+          content.$elems[1] = D.append(D.pre(),msg.xmsg);
+          self.toggleTextMode(e);
+        },
+        aftersend:function(){
+          delete e.$isToggling;
+          Chat.ajaxEnd();
+        }
+      });
+      return true;
+    };
+    
     /** Given a .message-row element, this function returns whethe the
         current user may, at least hypothetically, delete the message
         globally.  A user may always delete a local copy of a
         post. The server may trump this, e.g. if the login has been
         cancelled after this page was loaded.
@@ -681,10 +744,13 @@
           if(m.xmsg instanceof Array){
             // Used by Chat.reportErrorAsMessage()
             D.append(contentTarget, m.xmsg);
           }else{
             contentTarget.innerHTML = m.xmsg;
+            if(F.pikchr){
+              F.pikchr.addSrcView(contentTarget.querySelectorAll('svg.pikchr'));
+            }
           }
         }
         this.e.tab.addEventListener('click', this._handleLegendClicked, false);
         if(eXFrom){
           eXFrom.addEventListener('click', ()=>this.e.tab.click(), false);
@@ -739,14 +805,20 @@
                 btnDeleteGlobal.addEventListener('click', function(){
                   self.hide();
                   Chat.deleteMessage(eMsg);
                 });
               }
+              const toolbar2 = D.addClass(D.div(), 'toolbar');
+              D.append(this.e, toolbar2);
+              const btnToggleText = D.button("Toggle text mode");
+              btnToggleText.addEventListener('click', function(){
+                self.hide();
+                Chat.toggleTextMode(eMsg);
+              });
+              D.append(toolbar2, btnToggleText);
               if(eMsg.dataset.xfrom){
                 /* Add a link to the /timeline filtered on this user. */
-                const toolbar2 = D.addClass(D.div(), 'toolbar');
-                D.append(this.e, toolbar2);
                 const timelineLink = D.attr(
                   D.a(F.repoUrl('timeline',{
                     u: eMsg.dataset.xfrom,
                     y: 'a'
                   }), "User's Timeline"),
@@ -881,10 +953,11 @@
   */
   Chat.submitMessage = function f(){
     if(!f.spaces){
       f.spaces = /\s+$/;
     }
+    this.revealPreview(false);
     const fd = new FormData(this.e.inputForm)
     /* ^^^^ we don't really want/need the FORM element, but when
        FormData() is default-constructed here then the server
        segfaults, and i have no clue why! */;
     var msg = this.inputValue().trim();
@@ -952,12 +1025,21 @@
   };
 
   (function(){/*Set up #chat-settings-button */
     const settingsButton = document.querySelector('#chat-settings-button');
     const optionsMenu = E1('#chat-config-options');
-    const cbToggle = function(){
-      D.toggleClass([Chat.e.messagesWrapper, Chat.e.configArea], 'hidden');
+    const cbToggle = function(ev){
+      ev.preventDefault();
+      ev.stopPropagation();
+      if(Chat.e.configArea.classList.contains('hidden')){
+        D.removeClass(Chat.e.configArea, 'hidden');
+        D.addClass([Chat.e.messagesWrapper, Chat.e.previewArea], 'hidden');
+      }else{
+        D.addClass(Chat.e.configArea, 'hidden');
+        D.removeClass(Chat.e.messagesWrapper, 'hidden');
+      }
+      return false;
     };
     D.attr(settingsButton, 'role', 'button').addEventListener('click', cbToggle, false);
     Chat.e.configArea.querySelector('button').addEventListener('click', cbToggle, false);
     /* Settings menu entries... */
     const settingsOps = [{
@@ -995,11 +1077,11 @@
         F.toast.message("Image mode set to "+(v ? "inline" : "hyperlink")+".");
       }
     }];
 
     /** Set up selection list of notification sounds. */
-    if(false/*flip this to false to enable selection of audio files*/){
+    if(1){
       settingsOps.push({
         label: "Audible alerts",
         boolValue: ()=>Chat.settings.getBool('audible-alert'),
         callback: function(){
           const v = Chat.settings.toggle('audible-alert');
@@ -1009,40 +1091,10 @@
         }
       });
       Chat.setNewMessageSound(
         Chat.settings.getBool('audible-alert') ? F.config.chat.alertSound : false
       );
-    }else{
-      /* Disabled per chatroom discussion: selection list of audio files for
-         chat notification. */
-      settingsOps.selectSound = D.addClass(D.div(), 'menu-entry');
-      const selectSound = D.select();
-      D.append(settingsOps.selectSound,
-               D.append(D.span(),"Audio alert"),
-               selectSound);
-      D.option(selectSound, "", "(no audio)");
-      const firstSoundIndex = selectSound.options.length;
-      F.config.chat.alerts.forEach(function(a){
-        D.option(selectSound, a);
-      });
-      if(true===Chat.settings.getBool('audible-alert')){
-        selectSound.selectedIndex = firstSoundIndex;
-      }else{
-        selectSound.value = Chat.settings.get('audible-alert','');
-        if(selectSound.selectedIndex<0){
-          /*Missing file - removed after this setting was applied. Fall back
-            to the first sound in the list. */
-          selectSound.selectedIndex = firstSoundIndex;
-        }
-      }
-      selectSound.addEventListener('change',function(){
-        const v = this.value;
-        Chat.setNewMessageSound(v);
-        F.toast.message("Audio notifications "+(v ? "enabled" : "disabled")+".");
-        if(v) setTimeout(()=>Chat.playNewMessageSound(), 0);
-      }, false);
-      Chat.setNewMessageSound(selectSound.value);
     }/*audio notification config*/
     /**
        Build list of options...
     */
     settingsOps.forEach(function f(op){
@@ -1076,10 +1128,78 @@
     if(settingsOps.selectSound){
       D.append(optionsMenu, settingsOps.selectSound);
     }
     //settingsButton.click()/*for for development*/;
   })()/*#chat-settings-button setup*/;
+
+  (function(){/*set up message preview*/
+    const btnPreview = Chat.e.btnPreview;
+    Chat.setPreviewText = function(t){
+      this.revealPreview(true).e.previewContent.innerHTML = t;
+    };
+    /**
+       Reveals preview area if showIt is true, else hides it.
+       This also shows/hides other elements, "as appropriate."
+    */
+    Chat.revealPreview = function(showIt){
+      if(showIt){
+        D.removeClass(Chat.e.previewArea, 'hidden');
+        D.addClass([Chat.e.messagesWrapper, Chat.e.configArea],
+                   'hidden');
+      }else{
+        D.addClass(Chat.e.previewArea, 'hidden');
+        D.removeClass(Chat.e.messagesWrapper, 'hidden');
+      }
+      return this;
+    };
+    Chat.e.previewArea.querySelector('#chat-preview-close').
+      addEventListener('click', ()=>Chat.revealPreview(false), false);
+    let previewPending = false;
+    const elemsToEnable = [
+      btnPreview, Chat.e.btnSubmit,
+      Chat.e.inputSingle, Chat.e.inputMulti];
+    Chat.disableDuringAjax.push(btnPreview);
+    const submit = function(ev){
+      ev.preventDefault();
+      ev.stopPropagation();
+      if(previewPending) return false;
+      const txt = Chat.e.inputCurrent.value;
+      if(!txt){
+        Chat.setPreviewText('');
+        previewPending = false;
+        return false;
+      }
+      const fd = new FormData();
+      fd.append('content', txt);
+      fd.append('filename','chat.md'
+                /*filename needed for mimetype determination*/);
+      fd.append('render_mode',F.page.previewModes.wiki);
+      F.fetch('ajax/preview-text',{
+        payload: fd,
+        onload: (html)=>Chat.setPreviewText(html),
+        onerror: function(e){
+          F.fetch.onerror(e);
+          Chat.setPreviewText("ERROR: "+(
+            e.message || 'Unknown error fetching preview!'
+          ));
+        },
+        beforesend: function(){
+          D.disable(elemsToEnable);
+          Chat.ajaxStart();
+          previewPending = true;
+          Chat.setPreviewText("Loading preview...");
+        },
+        aftersend:function(){
+          previewPending = false;
+          D.enable(elemsToEnable);
+          Chat.ajaxEnd();
+        }
+      });
+      return false;
+    };
+    btnPreview.addEventListener('click', submit, false);
+  })()/*message preview setup*/;
   
   /** Callback for poll() to inject new content into the page.  jx ==
       the response from /chat-poll. If atEnd is true, the message is
       appended to the end of the chat list (for loading older
       messages), else the beginning (the default). */

Index: src/default.css
==================================================================
--- src/default.css
+++ src/default.css
@@ -1596,115 +1596,10 @@
   opacity: 0 !important;
   pointer-events: none !important;
   display: none !important;
 }
 
-/* Chat-related */
-body.chat span.at-name { /* for @USERNAME references */
-  text-decoration: underline;
-  font-weight: bold;
-}
-/* A wrapper for a single single chat message (one row of the UI) */
-body.chat .message-widget {
-  margin-bottom: 0.75em;
-  border: none;
-  display: flex;
-  flex-direction: column;
-  border: none;
-  align-items: flex-start;
-}
-body.chat.my-messages-right .message-widget.mine {
-  /* Right-aligns a user's own chat messages, similar to how
-     most mobile messaging apps do it. */
-  align-items: flex-end;
-}
-body.chat.my-messages-right .message-widget.notification {
-  /* Center-aligns a system-level notification message. */
-  align-items: center;
-}
-/* The content area of a message. */
-body.chat .message-widget-content {
-  display: inline-block;
-  border-radius: 0.25em;
-  border: 1px solid rgba(0,0,0,0.2);
-  box-shadow: 0.2em 0.2em 0.2em rgba(0, 0, 0, 0.29);
-  padding: 0.25em 0.5em;
-  margin-top: 0;
-  min-width: 9em /*avoid unsightly "underlap" with the neighboring
-                   .message-widget-tab element*/;
-  white-space: pre-wrap/*needed for multi-line edits*/;
-}
-body.chat.monospace-messages .message-widget-content,
-body.chat.monospace-messages textarea,
-body.chat.monospace-messages input[type=text]{
-  font-family: monospace;  
-}
-/* User name and timestamp (a LEGEND-like element) */
-body.chat .message-widget .message-widget-tab {
-  border-radius: 0.25em 0.25em 0 0;
-  margin: 0 0.25em 0em 0.15em;
-  padding: 0 0.5em 0.15em 0.5em;
-  cursor: pointer;
-  white-space: nowrap;
-}
-body.chat .fossil-tooltip.help-buttonlet-content {
-  font-size: 80%;
-}
-body.chat .message-widget .message-widget-tab .xfrom {
-  /* Element which holds the "this message is from user X" part
-     of the message banner. */
-  font-style: italic;
-  font-weight: bold;
-}
-/* The popup element for displaying message timestamps
-   and deletion controls. */
-body.chat .chat-message-popup {
-  font-family: monospace;
-  font-size: 0.8em;
-  text-align: left;
-  display: flex;
-  flex-direction: column;
-  align-items: stretch;
-  padding: 0.25em;
-  z-index: 200;
-}
-/* Full message timestamps. */
-body.chat .chat-message-popup > span { white-space: nowrap; }
-/* Container for the message deletion buttons. */
-body.chat .chat-message-popup > .toolbar {
-  padding: 0.2em;
-  margin: 0;
-  border: 2px inset rgba(0,0,0,0.3);
-  border-radius: 0.25em;
-  display: flex;
-  flex-direction: row;
-  justify-content: stretch;
-  flex-wrap: wrap;
-}
-body.chat .chat-message-popup > .toolbar > button {
-  flex: 1 1 auto;
-}
-/* The widget for loading more/older chat messages. */
-body.chat #load-msg-toolbar  {
-  border-radius: 0.25em;
-  padding: 0.1em 0.2em;
-  margin-bottom: 1em;
-}
-/* .all-done is set when chat has loaded all of the available
-   historical messages */
-body.chat #load-msg-toolbar.all-done {
-  opacity: 0.5;
-}
-body.chat #load-msg-toolbar > div {
-  display: flex;
-  flex-direction: row;
-  justify-content: stretch;
-  flex-wrap: wrap;
-}
-body.chat #load-msg-toolbar > div > button {
-  flex: 1 1 auto;
-}
 
 /* An icon element intended for use as a button/menu for
    accessing app-specific settings. */
 .settings-icon {
   /* Icon source: https://de.wikipedia.org/wiki/Datei:OOjs_UI_icon_settings.svg
@@ -1734,204 +1629,11 @@
   border: 1px outset rgba(127,127,127,1);
 }
 body.fossil-dark-style .settings-icon {
   filter: invert(100%);
 }
-/* "Chat-only mode" hides the site header/footer, showing only
-   the chat app. */
-body.chat.chat-only-mode{}
-body.chat #chat-settings-button {}
-/** Popup widget for the /chat settings. */
-body.chat .chat-settings-popup {
-  font-size: 0.8em;
-  text-align: left;
-  display: flex;
-  flex-direction: column;
-  align-items: stretch;
-  padding: 0.25em;
-  z-index: 200;
-}
-body.chat .chat-settings-popup > span {
-  vertical-align: middle;
-}
-body.chat .chat-settings-popup > span.menu-entry{
-  white-space: nowrap;
-  cursor: pointer;
-  border: 1px solid;
-  border-radius: 0.25em;
-  padding: 0.25em 0.5em;
-  display: flex;
-  flex-direction: row;
-  align-items: center;
-  justify-content: space-between;
-}
-body.chat .chat-settings-popup > span.menu-entry:hover {
-}
-body.chat .chat-settings-popup > span.menu-entry > .help-buttonlet {
-  vertical-align: middle;
-}
-body.chat .chat-settings-popup > span.menu-entry > span.button {
-  margin: 0.25em 0.2em;
-  padding: 0.25em;
-  flex: 1 1 auto/*eliminates dead no-click zones on the right*/;
-}
-body.chat .chat-settings-popup > span.menu-entry > input[type=checkbox] {
-  cursor: inherit;
-}
-body.chat .chat-settings-popup > select.menu-entry {
-  flex: 1 1 auto;
-  padding: 0;
-  cursor: pointer;
-  min-height: 2.5em;
-  border-radius: 0.25em;
-}
-body.chat .chat-settings-popup > select.menu-entry > option {
-  /*Recall that many browsers don't allow styling of OPTION
-    elements, or allow only very limited styling.*/
-}
-
-/** Container for the list of /chat messages. */
-body.chat #chat-messages-wrapper {
-  overflow: auto;
-  flex: 2 1 auto;
-  padding: 0 0.25em;
-}
-body.chat #chat-messages-wrapper.loading > * {
-  /* An attempt at reducing flicker when loading lots of messages. */
-  visibility: hidden;
-}
-body.chat div.content {
-  margin: 0;
-  padding: 0;
-  display: flex;
-  flex-direction: column-reverse;
-  /* ^^^^ In order to get good automatic scrolling of new messages on
-     the BOTTOM in bottom-up chat mode, such that they scroll up
-     instead of down, we have to use column-reverse layout, which
-     changes #chat-messages-wrapper's "gravity" for purposes of
-     scrolling! If we instead use flex-direction:column then each new
-     message pushes #chat-input-area down further off the screen!
- */
-  align-items: stretch;
-}
-/* Wrapper for /chat user input controls */
-body.chat #chat-input-area {
-  display: flex;
-  flex-direction: column;
-  padding: 0.5em 1em;
-  border-bottom: none;
-  border-top: 1px solid black;
-  margin: 0.5em 1em 0 1em;
-  position: initial /*sticky currently disabled due to scrolling-related issues*/;
-  bottom: 0;
-}
-body.chat:not(.chat-only-mode) #chat-input-area{
-  /* Safari user reports that 2em is necessary to keep the file selection
-     widget from overlapping the page footer, whereas a margin of 0 is fine
-     for FF/Chrome (and 2em is a *huge* waste of space for those). */
-  margin-bottom: 0;
-}
-
-/* Widget holding the chat message input field, send button, and
-   settings button. */
-body.chat #chat-input-line {
-  display: flex;
-  flex-direction: row;
-  margin-bottom: 0.25em;
-  align-items: self-start;
-}
-body.chat #chat-input-line > input[type=submit],
-body.chat #chat-input-line > #chat-settings-button,
-body.chat #chat-input-line > button {
-  flex: 1 5 auto;
-  max-width: 6em;
-  margin: 0 0.25em;
-}
-body.chat #chat-input-line > button {
-  max-width: 4em;
-}
-body.chat #chat-input-line > #chat-settings-button{
-  margin: 0 0 0 0.25em;
-  max-width: 2em;
-}
-body.chat #chat-input-line > input[type=text],
-body.chat #chat-input-line > textarea {
-  flex: 5 1 auto;
-}
-/* Widget holding the file selection control and preview */
-body.chat #chat-input-file-area  {
-  display: flex;
-  flex-direction: row;
-  align-items: center;
-  flex-wrap: wrap;
-}
-body.chat #chat-input-file-area > .file-selection-wrapper {
-  align-self: flex-start;
-  margin-right: 0.5em;
-  flex: 0 1 auto;
-  padding: 0.25em 0.25em 0.25em 0;
-}
-body.chat #chat-input-file-area .file-selection-wrapper > * {
-  vertical-align: middle;
-  margin: 0;
-}
-body.chat #chat-input-file {
-  border:1px solid rgba(0,0,0,0);/*avoid UI shift during drop-targeting*/
-  border-radius: 0.25em;
-  padding: 0.25em;
-}
-body.chat #chat-input-file > input {
-  flex: 1 0 auto;
-}
-/* Indicator when a drag/drop is in progress */
-body.chat #chat-input-file.dragover {
-  border: 1px dashed green;
-}
-/* Widget holding the details of a selected/dropped file/image. */
-body.chat #chat-drop-details {
-  flex: 0 1 auto;
-  padding: 0.5em 1em;
-  margin-left: 0.5em;
-  white-space: pre;
-  font-family: monospace;
-}
-
-body.chat #chat-drop-details img {
-  max-width: 45%;
-  max-height: 45%;
-}
-body.chat #chat-config {
-  /* /chat configuration widget */
-  display: flex;
-  flex-direction: column;
-  flex: 1 0 auto;
-  overflow: auto;
-  flex: 2 1 auto;
-  padding: 0 0.25em;
-}
-body.chat #chat-config > button {
-  padding: 0.5em;
-  flex: 0 1 auto;
-  margin: 0.25em 0;
-}
-body.chat #chat-config #chat-config-options {
-  /* /chat config options go here */
-  flex: 1 1 auto;
-  display: flex;
-  flex-direction: column;
-  overflow: auto;
-}
-body.chat #chat-config #chat-config-options .menu-entry {
-  display: flex;
-  align-items: center;
-  flex-direction: row;
-  flex-wrap: wrap;
-  padding: 1em;
-}
-body.chat #chat-config #chat-config-options .menu-entry > *:first-child {
-  margin-right: 1em;
-}
+
 input[type="checkbox"].diff-toggle {
   float: right;
 }
 
 body.branch .brlist > table > tbody > tr:hover:not(.selected),

Index: src/main.mk
==================================================================
--- src/main.mk
+++ src/main.mk
@@ -265,10 +265,11 @@
   $(SRCDIR)/sounds/c.wav \
   $(SRCDIR)/sounds/d.wav \
   $(SRCDIR)/sounds/e.wav \
   $(SRCDIR)/sounds/f.wav \
   $(SRCDIR)/style.admin_log.css \
+  $(SRCDIR)/style.chat.css \
   $(SRCDIR)/style.fileedit.css \
   $(SRCDIR)/style.wikiedit.css \
   $(SRCDIR)/tree.js \
   $(SRCDIR)/useredit.js \
   $(SRCDIR)/wiki.wiki

Index: src/markdown.c
==================================================================
--- src/markdown.c
+++ src/markdown.c
@@ -1665,10 +1665,11 @@
 
   if( !size || data[0]!='#' ) return 0;
 
   while( level<size && level<6 && data[level]=='#' ){ level++; }
   for(i=level; i<size && (data[i]==' ' || data[i]=='\t'); i++);
+  if ( i == level ) return parse_paragraph(ob, rndr, data, size);
   span_beg = i;
 
   for(end=i; end<size && data[end]!='\n'; end++);
   skip = end;
   if( end<=i ) return parse_paragraph(ob, rndr, data, size);

ADDED   src/style.chat.css
Index: src/style.chat.css
==================================================================
--- /dev/null
+++ src/style.chat.css
@@ -0,0 +1,348 @@
+/* Chat-related */
+body.chat span.at-name { /* for @USERNAME references */
+  text-decoration: underline;
+  font-weight: bold;
+}
+/* A wrapper for a single single chat message (one row of the UI) */
+body.chat .message-widget {
+  margin-bottom: 0.75em;
+  border: none;
+  display: flex;
+  flex-direction: column;
+  border: none;
+  align-items: flex-start;
+}
+body.chat.my-messages-right .message-widget.mine {
+  /* Right-aligns a user's own chat messages, similar to how
+     most mobile messaging apps do it. */
+  align-items: flex-end;
+}
+body.chat.my-messages-right .message-widget.notification {
+  /* Center-aligns a system-level notification message. */
+  align-items: center;
+}
+/* The content area of a message. */
+body.chat .message-widget-content {
+  display: inline-block;
+  border-radius: 0.25em;
+  border: 1px solid rgba(0,0,0,0.2);
+  box-shadow: 0.2em 0.2em 0.2em rgba(0, 0, 0, 0.29);
+  padding: 0.25em 0.5em;
+  margin-top: 0;
+  min-width: 9em /*avoid unsightly "underlap" with the neighboring
+                   .message-widget-tab element*/;
+  white-space: normal;
+}
+body.chat.monospace-messages .message-widget-content,
+body.chat.monospace-messages textarea,
+body.chat.monospace-messages input[type=text]{
+  font-family: monospace;  
+}
+body.chat .message-widget-content > * {
+  margin: 0;
+  padding: 0;
+}
+body.chat .message-widget-content > pre {
+  white-space: pre-wrap;
+}
+body.chat .message-widget-content > .markdown > *:first-child {
+  margin-top: 0;
+}
+body.chat .message-widget-content > .markdown > *:last-child {
+  margin-bottom: 0;
+}
+/* User name and timestamp (a LEGEND-like element) */
+body.chat .message-widget .message-widget-tab {
+  border-radius: 0.25em 0.25em 0 0;
+  margin: 0 0.25em 0em 0.15em;
+  padding: 0 0.5em 0.15em 0.5em;
+  cursor: pointer;
+  white-space: nowrap;
+}
+body.chat .fossil-tooltip.help-buttonlet-content {
+  font-size: 80%;
+}
+body.chat .message-widget .message-widget-tab .xfrom {
+  /* Element which holds the "this message is from user X" part
+     of the message banner. */
+  font-style: italic;
+  font-weight: bold;
+}
+/* The popup element for displaying message timestamps
+   and deletion controls. */
+body.chat .chat-message-popup {
+  font-family: monospace;
+  font-size: 0.8em;
+  text-align: left;
+  display: flex;
+  flex-direction: column;
+  align-items: stretch;
+  padding: 0.25em;
+  z-index: 200;
+}
+/* Full message timestamps. */
+body.chat .chat-message-popup > span { white-space: nowrap; }
+/* Container for the message deletion buttons. */
+body.chat .chat-message-popup > .toolbar {
+  padding: 0;
+  margin: 0;
+  border: 2px inset rgba(0,0,0,0.3);
+  border-radius: 0.25em;
+  display: flex;
+  flex-direction: row;
+  justify-content: stretch;
+  flex-wrap: wrap;
+  align-items: center;
+}
+body.chat .chat-message-popup > .toolbar > * {
+  margin: 0.35em;
+}
+body.chat .chat-message-popup > .toolbar > button {
+  flex: 1 1 auto;
+}
+/* The widget for loading more/older chat messages. */
+body.chat #load-msg-toolbar  {
+  border-radius: 0.25em;
+  padding: 0.1em 0.2em;
+  margin-bottom: 1em;
+}
+/* .all-done is set when chat has loaded all of the available
+   historical messages */
+body.chat #load-msg-toolbar.all-done {
+  opacity: 0.5;
+}
+body.chat #load-msg-toolbar > div {
+  display: flex;
+  flex-direction: row;
+  justify-content: stretch;
+  flex-wrap: wrap;
+}
+body.chat #load-msg-toolbar > div > button {
+  flex: 1 1 auto;
+}
+/* "Chat-only mode" hides the site header/footer, showing only
+   the chat app. */
+body.chat.chat-only-mode{}
+body.chat #chat-settings-button {}
+/** Popup widget for the /chat settings. */
+body.chat .chat-settings-popup {
+  font-size: 0.8em;
+  text-align: left;
+  display: flex;
+  flex-direction: column;
+  align-items: stretch;
+  padding: 0.25em;
+  z-index: 200;
+}
+body.chat .chat-settings-popup > span {
+  vertical-align: middle;
+}
+body.chat .chat-settings-popup > span.menu-entry{
+  white-space: nowrap;
+  cursor: pointer;
+  border: 1px solid;
+  border-radius: 0.25em;
+  padding: 0.25em 0.5em;
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  justify-content: space-between;
+}
+body.chat .chat-settings-popup > span.menu-entry:hover {
+}
+body.chat .chat-settings-popup > span.menu-entry > .help-buttonlet {
+  vertical-align: middle;
+}
+body.chat .chat-settings-popup > span.menu-entry > span.button {
+  margin: 0.25em 0.2em;
+  padding: 0.25em;
+  flex: 1 1 auto/*eliminates dead no-click zones on the right*/;
+}
+body.chat .chat-settings-popup > span.menu-entry > input[type=checkbox] {
+  cursor: inherit;
+}
+body.chat .chat-settings-popup > select.menu-entry {
+  flex: 1 1 auto;
+  padding: 0;
+  cursor: pointer;
+  min-height: 2.5em;
+  border-radius: 0.25em;
+}
+body.chat .chat-settings-popup > select.menu-entry > option {
+  /*Recall that many browsers don't allow styling of OPTION
+    elements, or allow only very limited styling.*/
+}
+
+/** Container for the list of /chat messages. */
+body.chat #chat-messages-wrapper {
+  overflow: auto;
+  flex: 2 1 auto;
+  padding: 0 0.25em;
+}
+body.chat #chat-messages-wrapper.loading > * {
+  /* An attempt at reducing flicker when loading lots of messages. */
+  visibility: hidden;
+}
+body.chat div.content {
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column-reverse;
+  /* ^^^^ In order to get good automatic scrolling of new messages on
+     the BOTTOM in bottom-up chat mode, such that they scroll up
+     instead of down, we have to use column-reverse layout, which
+     changes #chat-messages-wrapper's "gravity" for purposes of
+     scrolling! If we instead use flex-direction:column then each new
+     message pushes #chat-input-area down further off the screen!
+ */
+  align-items: stretch;
+}
+/* Wrapper for /chat user input controls */
+body.chat #chat-input-area {
+  display: flex;
+  flex-direction: column;
+  padding: 0.5em 0 0 0;
+  border-bottom: none;
+  border-top: 1px solid black;
+  margin: 0.5em 0;
+  position: initial /*sticky currently disabled due to scrolling-related issues*/;
+  bottom: 0;
+}
+body.chat:not(.chat-only-mode) #chat-input-area{
+  /* Safari user reports that 2em is necessary to keep the file selection
+     widget from overlapping the page footer, whereas a margin of 0 is fine
+     for FF/Chrome (and 2em is a *huge* waste of space for those). */
+  margin-bottom: 0;
+}
+
+/* Widget holding the chat message input field, send button, and
+   settings button. */
+body.chat #chat-input-line {
+  display: flex;
+  flex-direction: row;
+  margin-bottom: 0.25em;
+  align-items: stretch;
+}
+body.chat #chat-input-line.single-line {
+  flex-wrap: wrap;
+}
+body.chat #chat-edit-buttons {
+  display: flex;
+  flex-direction: column;
+  justify-content: space-between;
+}
+body.chat #chat-input-line.single-line #chat-edit-buttons {
+  flex-direction: row;
+}
+body.chat #chat-edit-buttons > * {
+  /*flex: 1 5 auto;*/
+  max-width: 6em;
+  margin: 0 0.25em;
+}
+body.chat #chat-input-line > button {
+  max-width: 4em;
+}
+body.chat #chat-input-line > #chat-settings-button{
+  margin: 0 0 0 0.25em;
+  max-width: 2em;
+}
+body.chat #chat-input-line > input[type=text],
+body.chat #chat-input-line > textarea {
+  flex: 5 1 auto;
+  max-width: revert;
+  min-width: 24em;
+}
+/* Widget holding the file selection control and preview */
+body.chat #chat-input-file-area  {
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+  flex-wrap: wrap;
+}
+body.chat #chat-input-file-area > .file-selection-wrapper {
+  align-self: flex-start;
+  margin-right: 0.5em;
+  flex: 0 1 auto;
+  padding: 0.25em 0.25em 0.25em 0;
+  white-space: nowrap;
+}
+body.chat #chat-input-file-area .file-selection-wrapper > * {
+  vertical-align: middle;
+  margin: 0;
+}
+body.chat #chat-input-file {
+  border:1px solid rgba(0,0,0,0);/*avoid UI shift during drop-targeting*/
+  border-radius: 0.25em;
+  padding: 0.25em;
+}
+body.chat #chat-input-file > input {
+  flex: 1 0 auto;
+}
+/* Indicator when a drag/drop is in progress */
+body.chat #chat-input-file.dragover {
+  border: 1px dashed green;
+}
+/* Widget holding the details of a selected/dropped file/image. */
+body.chat #chat-drop-details {
+  flex: 0 1 auto;
+  padding: 0.5em 1em;
+  margin-left: 0.5em;
+  white-space: pre;
+  font-family: monospace;
+}
+
+body.chat #chat-drop-details img {
+  max-width: 45%;
+  max-height: 45%;
+}
+
+body.chat #chat-config,
+body.chat #chat-preview {
+  /* /chat configuration widget */
+  display: flex;
+  flex-direction: column;
+  overflow: auto;
+  flex: 2 1 auto;
+  padding: 0;
+  margin: 0;
+  align-items: stretch;
+  min-height: 6em;
+}
+body.chat #chat-config #chat-config-options {
+  /* /chat config options go here */
+  flex: 1 1 auto;
+  display: flex;
+  flex-direction: column;
+  overflow: auto;
+}
+body.chat #chat-config #chat-config-options .menu-entry {
+  display: flex;
+  align-items: center;
+  flex-direction: row;
+  flex-wrap: wrap;
+  padding: 1em;
+}
+body.chat #chat-config #chat-config-options .menu-entry > *:first-child {
+  margin-right: 1em;
+}
+body.chat #chat-preview #chat-preview-content {
+  overflow: auto;
+  flex: 1 1 auto;
+  padding: 0.5em;
+  border: 1px dotted;
+}
+body.chat #chat-preview #chat-preview-content > * {
+  margin: 0;
+  padding: 0;
+}
+body.chat #chat-preview #chat-preview-buttons {
+  flex: 0 1 auto;
+  display: flex;
+  flex-direction: column;
+}
+body.chat #chat-config > button,
+body.chat #chat-preview #chat-preview-buttons > button {
+  padding: 0.5em;
+  flex: 0 1 auto;
+  margin: 0.25em 0;
+}

Index: win/Makefile.mingw
==================================================================
--- win/Makefile.mingw
+++ win/Makefile.mingw
@@ -674,10 +674,11 @@
   $(SRCDIR)/sounds/c.wav \
   $(SRCDIR)/sounds/d.wav \
   $(SRCDIR)/sounds/e.wav \
   $(SRCDIR)/sounds/f.wav \
   $(SRCDIR)/style.admin_log.css \
+  $(SRCDIR)/style.chat.css \
   $(SRCDIR)/style.fileedit.css \
   $(SRCDIR)/style.wikiedit.css \
   $(SRCDIR)/tree.js \
   $(SRCDIR)/useredit.js \
   $(SRCDIR)/wiki.wiki

Index: win/Makefile.msc
==================================================================
--- win/Makefile.msc
+++ win/Makefile.msc
@@ -616,10 +616,11 @@
         "$(SRCDIR)\sounds\c.wav" \
         "$(SRCDIR)\sounds\d.wav" \
         "$(SRCDIR)\sounds\e.wav" \
         "$(SRCDIR)\sounds\f.wav" \
         "$(SRCDIR)\style.admin_log.css" \
+        "$(SRCDIR)\style.chat.css" \
         "$(SRCDIR)\style.fileedit.css" \
         "$(SRCDIR)\style.wikiedit.css" \
         "$(SRCDIR)\tree.js" \
         "$(SRCDIR)\useredit.js" \
         "$(SRCDIR)\wiki.wiki"
@@ -1224,10 +1225,11 @@
 	echo "$(SRCDIR)\sounds/c.wav" >> $@
 	echo "$(SRCDIR)\sounds/d.wav" >> $@
 	echo "$(SRCDIR)\sounds/e.wav" >> $@
 	echo "$(SRCDIR)\sounds/f.wav" >> $@
 	echo "$(SRCDIR)\style.admin_log.css" >> $@
+	echo "$(SRCDIR)\style.chat.css" >> $@
 	echo "$(SRCDIR)\style.fileedit.css" >> $@
 	echo "$(SRCDIR)\style.wikiedit.css" >> $@
 	echo "$(SRCDIR)\tree.js" >> $@
 	echo "$(SRCDIR)\useredit.js" >> $@
 	echo "$(SRCDIR)\wiki.wiki" >> $@

Index: www/changes.wiki
==================================================================
--- www/changes.wiki
+++ www/changes.wiki
@@ -39,10 +39,15 @@
   *  The [/help?cmd=all|fossil all git status] command only shows reports for
      the subset of repositories that have a configured Git export.
   *  Enhanced the [/help?cmd=/chat|/chat page] configuration and added the ability
      for a repository administrator to [./chat.md#notifications|extend the
      selection of notification sounds via unversioned files].
+  *  The [/help?cmd=/chat|/chat] messages now use fossil's full complement of
+     markdown features, instead of the prior small subset of markup it
+     previously supported. This retroactively applies to all chat messages,
+     as they are markdown-processed when they are sent instead of when they
+     are saved. See [./chat.md#usage|the chat docs] for more details.
 
 <h2 id='v2_16'>Changes for Version 2.16 (2021-07-02)</h2>
   *  <b>Security:</b> Fix the client-side TLS so that it verifies that the
      server hostname matches its certificate.
   *  The default "ssh" command on Windows is changed to "ssh" instead of the

Index: www/chat.md
==================================================================
--- www/chat.md
+++ www/chat.md
@@ -4,15 +4,15 @@
 
 As of version 2.14,
 Fossil supports a developer chatroom feature.  The chatroom provides an
 ephemeral discussion venue for insiders.  Design goals include:
 
-  *  **Simple but functional** &rarr; Fossil chat is designed to provide a
-     convenient real-time communication mechanism for geographically
-     dispersed developers.  Fossil chat is *not* intended
-     as a replacement or 
-     competitor for IRC, Slack, Discord, Telegram, Google Hangouts, etc.
+  *  **Simple but functional** &rarr;
+     Fossil chat is designed to provide a convenient real-time
+     communication mechanism for geographically dispersed developers.
+     Fossil chat is *not* intended as a replacement or competitor for
+     IRC, Slack, Discord, Telegram, Google Hangouts, etc.
 
   *  **Low administration** &rarr;
      You can activate the chatroom in seconds without having to
      mess with configuration files or install new software.
      In an existing [server setup](./server/),
@@ -53,34 +53,23 @@
 behavior of chat, though the default settings are reasonable so in most
 cases those settings can be ignored.  The settings control things like
 the amount of time that chat messages are retained before being purged
 from the repository database.
 
-## Usage
+## <a id="usage"></a>Usage
 
 For users with appropriate permissions, simply browse to the
 [/chat](/help?cmd=/chat) to start up a chat session.  The default
 skin includes a "Chat" entry on the menu bar on wide screens for
 people with chat privilege.  There is also a "Chat" option on
 the [Sitemap page](/sitemap), which means that chat will appear
 as an option under the hamburger menu for many [skins](./customskin.md).
 
-Message text is delivered verbatim.  There is no markup.  However,
-the chat system does try to identify and tag hyperlinks, as follows:
-
-  *  Any word that begins with "http://" or "https://" is assumed
-     to be a hyperlink and is tagged.
-
-  *  Text within `[...]` is parsed, and it if is a valid hyperlink
-     target (according to the way that [Fossil Wiki](/wiki_rules) or
-     [Markdown](/md_rules) understand hyperlinks), then that text is
-     tagged. Note that only URLs and Fossil-internal constructs such
-     as checkin hashes and wiki pages names are recognized here, not
-     constructs such as `[URL | label]` or `[label](URL)`.
-
-Apart from adding hyperlink anchor tags to bits of text that look
-like hyperlinks, no changes are made to the input text.
+As of version 2.17, chat messages are subject to [fossil's
+full range of markdown processing](/md_rules). Because chat messages are
+stored as-is when they arrive from a client, this change applies
+retroactively to messages stored by previous fossil versions.
 
 Files may be sent via chat using the file selection element at the
 bottom of the page. If the desktop environment system supports it,
 files may be dragged and dropped onto that element. Files are not
 automatically sent - selection of a file can be cancelled using the