Salut à Toi (or SàT: "Hi to You") is an XMPP/Jabber client with multi-frontends. You can use it on a desktop (Wix), with a console interface (Primitivus), as a command-line tool (jp), or on the Web (Libervia). A plugin architecture is used to make it modular. With SàT, you can perform all the expected XMPP functions (instant messaging, multi-user chat, file transfert, etc.), but you can also use your email client (MUA) to read and send your XMPP messages, play games, do microblogging, pipe Unix command results, make scripts, etc.
Jaro Mail is an integrated suite of interoperable tools for GNU/Linux and Apple/OS X to manage email communication in a private way, without relying on online services (in fact, encouraging users to store email locally). It mainly features a system for mailinglist filtering, address-book integrated whitelisting, and long-term email storage and archiving with functions for fast search and usage statistics. It makes internal use of customized versions of popular Unix tools like Mutt, Fetchmail, Procmail, Mairix, and Msmtp.