ftp client software

Invoice Client Manager organizes and runs the Client side of a small businesses

Encrypted BBS style client for chat, messaging, and transfers.

Fast and reliable FTP client.

Waveboard is a client software for Google Wave

Robust email client from the makers of BBEdit, now free.

A beautifully designed and very functional Twitter Client

Syrinx is a fully customizable twitter client designed for Leopard (OS X 10.5+).

S3 Browser is a free client interface for Amazon S3 Service.

Subversion client.