Imap-js is a clientside IMAP client. It runs in the browser, communicating directly with the IMAP server via a long-polling comet proxy. It's written for the golf web framework.
I need to have some kind of webmail access to my IMAP server. However, I don't like running a web app frontend for it (like RoundCube, SquirrelMail, etc.), because I don't like the possibility of security vulnerabilities common to complex web apps. Email is not something that I can afford to have hacked.
So, this project will hopefully produce a fully clientside webmail solution. Then the only worry will be whether the IMAP daemon itself is secure, which is something I'd need to take care of anyway, with or without webmail.
Progress so far...
It can log in, list all folders, and get info (like how many unread messages, etc.).
Get golf source and build it:
Edit plugins/config.js to reflect your IMAP server and port. (No SSL at the moment--it normally is connecting on a local socket on the server.)
Then, clone this git repo and from the repo directory do:
golf . longpoll.war
You should be able to point your browser at http://example.com:4653/imap-js/ and log into your IMAP server. (Replace example.com with the real hostname, obviously.)