Opera has an about:about, but it doesn't list all about:X pages. It does gives version information, browser identification and folders where it has files (that one is very handy).
I find that my posts to their mailing lists don't go through half the time. I have no idea why. I guess my cordial comments fall through the cracks some times.
Don't go through as in a technical problem or don't get a response?
I'd be happy to ask around and try to see what might be going on with a technical problem if you send me the details of what happens when you try to post.
I'm not sure if it's a technical problem or if it's moderation, but I usually post from my email client and then later look on Google Groups to see if they show up there. Some times they do, some times not. When I post from Google Groups they seem to go through and show up twice, so I try and avoid posting that way.
It's a technical problem. The lists have a weird two-way email/NNTP bridge, and Google Groups is on the NNTP side. Frequently Google Groups falls behind the actual newsgroup, sometimes for several days at a time, e.g. http://bugzil.la/667637
When that happens, you can point an NNTP client (like Thunderbird) at news.mozilla.org to see if your message actually went through.
So Mozilla is jwz's name for the Netscape code that they open sourced. Does anybody know if there is a continual code-base going back through Firefox to Mozilla to Netscape to Mosaic? In which case, they could claim, they invented it all.
jwz mentions that he was unsuccessful lobbying the release of the 3.0 source.[1] For the purposes of this discussion (since you only ask about the browser here), according to Brendan, 4 was like 3.[2] Seibel mentions there that Brendan says he tried to get it released, too. The big rewrite that everybody talks about is Gecko (under the stewardship of Gessner, I think), when 5 got ditched and the next release jumped to 6. It's still listed on the MXR homepage (under Classic). Then, ho-ho, there came another new flavor at the genesis of Firefox proper, Aviary, which is also indexed on MXR. I don't know what sets it apart from pre-Aviary besides that it ditched the old XPInstall stuff. (Yeah, XPIs still exist, but most people don't realize that's not XPInstall anymore. That's the new-ish "toolkit" install system.)
From my vague understanding of the history, Mozilla code goes all the way to Netscape. I think Netscape did a giant rewrite, so it probably doesn't go back further.
Technically, firefox is the browser front-end to the Mozilla codebase, and Thunderbird is another front-end of the same product. I think what used to be called the Mozilla suite is now seamonkey. So I think it all comes from the Netscape release.