Never heard of SeaMonkey, but I'll check it out.
Have you used SeaMonkey to write posts on FR? Curious, because the user side of FR uses old HTML code like <font> and doesn't allow in-line styling using CSS.
My profile page is pasted from the SeaMonkey HTML editor. I think you’d call it old style. I don’t use the editor to create FR posts unless I’m adding images, various fonts, links, blockquoting, etc. But I use the browser as my primary browser === it is Mozilla based.
http://www.seamonkey-project.org/
Seamonkey is the old Mozilla full featured suite from which the Firefox browser branched off. I have an old version which I use when I want to insert photos in a FR post or do something unusual; I then cut the relevant portion of the code and paste it into my posting window in Firefox.
It’s one of the easier HTML editors to use.