SeaMonkey Composer uses a plaintext editor to edit HTML source (editortype="text").

Plain and simple, reliable, gets the job done… as long as you don’t want any syntax highlighting, line numbers, code folding, auto-completion, etc.: it’s a Notepad, no more, no less.

Nvu used an html editor to edit HTML source (editortype="html"):

  • a colored source view of the current page is generated, modified to add line numbers and sent to the html editor
  • after this html view of the html source has been edited in wysiwyg, it’s exported to text and the HTML document is rebuilt from that text.

I think this isn’t an acceptable solution:

  • all these successive conversions are too tricky: this “Source tab” was very buggy in Nvu’s and has caused most of the crashes and data losses
  • this pseudo syntax highlighting can’t be updated as you modify the code, so what’s the point?
  • the html editor is a poor text editor: it’s slow, the caret gets stuck sometimes, requiring to use the mouse.

I guess it’s better than nothing but as far as I’m concerned, I prefer a Notepad.


Firebug uses a browser to display and edit the HTML source. This brings a decent syntax highlighting and a good code folding, and it’s very handy for small modifications.

However, it’s nowhere near a text editor either: it’s slow, it’s impossible to use without a mouse, and it’s very specific to HTML and CSS. It makes a lot of sense in Firebug and might be interesting in a web editor like KompoZer, but it doesn’t claim to be a code editor.


Komodo relies on SciMoz, i.e. a Scintilla binding. I think it’s the best possible editor component for Mozilla apps: it’s very fast and lightweight, it has the best lexer I know (better than Vim’s imho) and a good code completion. Its code folding feature works well with all languages… except with HTML, unfortunately.

The main drawback is that SciMoz is very difficult to embed into a non-Komodo app. I believe ActiveState would like to share the effort on SciMoz with Mozilla, and an <editor editortype="scintilla"> element would sure rock… but unfortunately this doesn’t seem to be a priority for Mozilla. I sure wish it was!

Speaking of KompoZer, the solution would be to build KompoZer on OpenKomodo: KompoZer would become quite heavy-weight but it would remain acceptable compared to Expression Web or DreamWeaver.


The good news might come from Bespin:

We’ve also been asked whether we’d like to make it easy for folks to embed Bespin’s canvas editor in their own non-Bespin projects. Absolutely we do. Bespin will eventually spin out three projects:
  1. The Bespin project: an on-line code editor (i.e., the project we’ve currently announced)
  2. Thunderhead: a canvas/JS GUI toolkit
  3. (To Be Named Editor): a stand-alone canvas editor that you can embed

I still doubt Bespin can come close to Scintilla in terms of performances and features; but having an embeddable, standalone editor that could easily be used in any Mozilla project would be a great improvement, despite all other limitations.

So far I intended to use SciMoz in KompoZer 0.9, but Bespin might bring a very interesting alternative — especially if KompoZer merges with SeaMonkey Composer. I’ll keep a close eye on this standalone canvas editor project!