The IMAP Compatibility Matrix

There's a great discussion going on in the comments of my post about replacing IMAP, and also on YCombinator's Hacker News.

One frequent point made about my proposal is that IMAP already has a number of extensions that do things I suggested, such as the THREADS, SEARCH, and IDLE commands for conversations, search, and long polling ("push").

Commenter Bron (who works on a popular IMAP server) writes:

Also, IMAP plus a random mix of extentions becomes a HUGE compatibility matrix, and you have to offer fallback from all the nice stuff to really shitty workarounds just in case the server doesn't support a feature that makes your life bearable.

So - I'd love to see a decent competitor to IMAP as a protocol. If nothing else because it would reduce the compatibility matrix. Alternatively, I'd be happy for an IMAP5 to be defined which included all the good extentions - so anything which advertised support for IMAP5 had to support them.

Defining an IMAP5 standard might be a good alternative than something like reMAP, and adoption might be much faster. However, a potential IMAP5 would still remain a protocol inaccessible to many developers so it might not unleash the storm of creativity I'm hoping for.

Keep those comments coming.