telnet client

Quassel IRC is a modern, distributed IRC client based on the Qt4 framework.

emule client which enhanced emule Xtreme Mod

SmVDC++ is a client for the direct connect network based on Airdc++.

Kommute is a cross platfrom file sharing client using the anonymous network MUTE

Bulk Email Client for Sending Personalized Text or HTML Messages

It's scalable too very high numbers of feeds and can be used in multi-client

Remote File Server / FTP Client, Drag & Drop, Easy Secure Share & Access, FTP

Turbo charged FTP client for Mac OS X with many advanced features

Mercury Messenger (previously called dMSN) is a Java-based MSN client.

Treeview for ASP.NET (client model, ADO.NET, load-on-demand, drag-and-drop, ...)