Tsung is a distributed load testing tool. It is protocol-independent and can currently be used to stress HTTP, WebDAV, PostgreSQL, MySQL, LDAP, AMQP, and XMPP/Jabber servers. It simulates user behavior using an XML description file, reports many measurements in real time (statistics can be customized with transactions, and graphics generated using gnuplot). For HTTP, it supports 1.0 and 1.1, has a proxy mode to record sessions, supports GET, POST, PUT, and DELETE methods, cookies, and basic/digest authentication. It also has support for SSL, WebSocket, and BOSH.
climm (CLI-based Multi-Messenger) is a portable, small, yet powerful console-based ICQ and XMPP client. It supports password changing, auto-away, creation of new accounts, and other features that makes it a very complete yet simple client. It is able to send and receive messages from the ICQ network, list users that are offline and online (including their online status), search for users by email address, and look up basic (name, UIN, email) information. climm was formerly known as mICQ.
Bip is an IRC proxy that supports replaying logged conversation and multiple clients on one IRC server connection. It has a handy logging directory structure. It is multi-user and has a flexible configuration. Some of its configuration can be changed at runtime with special IRC commands.