Lurker is a mailing list archiver designed for capacity, speed, simplicity, and configurability in that order. Noteworthy features include: google-style searching on all fields, chronology preserving threads, multilingual, and attachment support.
The ListServer is an application for serving up lists of "items" and their contents via an internet connection. All the usual suspects, FTP, HTTP, SMTP, NNTP etc are supported. The "items" can be anything. Designed for the santiagobis egroup.
kLJ is a LiveJournal client for KDE, based on the official win32 client, providing the same features and some additions as they are requested. (http://www.livejournal.com/)