&gt; I could keep paraphrasing but it&#x27;s basically just &quot;gmail rawks&quot; over and over and over again in different words.<p>Given that the author of the mail uses Thunderbird as her mail client, it&#x27;s fairly unlikely that &quot;gmail rawks&quot; is what she&#x27;s actually thinking here.<p>But of course it&#x27;s easier to snark about &quot;built on identical platforms&quot; without worrying about technical realities like &quot;security and the need to do multiprocess require some fundamental changes to the way networking works in Gecko and changing the IMAP implementation in Thunderbird accordingly is... let&#x27;s say rather involved&quot;.<p>Note that we (Gecko developers) have in fact taken great pains to not break Thunderbird so far, and are carrying some significant technical debt as a result.  The big question is whether we should keep doing that or whether we should invest more heavily in Thunderbird to rewrite large pieces to allow Gecko to stop carrying that technical debt, or to decouple Thunderbird and Firefox in some way so that we can make the changes Firefox needs without breaking thunderbird, or something else.  This mail is part of the discussion about that; mostly about figuring out which of those options we should really pursue.