I released a new webmail application that I've been working on lately: www.xuheki.com — it is a fully featured IMAP client that works in a browser. Xuheki itself is free under the GNU GPL v3 and it's powered by DynarchLIB (but it also has quite some requirements on the server side).
Xuheki uses an updated version of DynarchLIB which isn't yet present here. I will publish it in the next few days, although documentation still lags behind...
