Actually, they're in the middle of landing in Mozilla's repository [1], and as of last week some time they haven't gotten their nightly builds back up yet. It

Actually, they're in the middle of landing in Mozilla's repository [1], and as of last week some time they haven't gotten their nightly builds back up yet. It lives in comm-central, though, along with Thunderbird/Seamonkey and not Firefox (/Gonk/etc). I have no actual knowledge of why Tor picked Instantbird over Pidgin; idle speculation says they're already stuck with Firefox anyway (TBB), so the additional risk from JavaScript-based instant messaging protocols isn't high. I do not believe Instantbird supports DNS SRV at all at this point, and it just uses the same infrastructure Mozilla uses for browsing to make connections, so presumably that's already safe. (Bias warning: I hang out in Instantbird's IRC channel and have made a patch or two. I don't think any of the above would change otherwise, though.) [1] https://hg.mozilla.org/comm-central/file/tip/im https://hg.mozilla.org/comm-central/file/tip/im