See the page of text messaging abbreviations in the Quick Reference section of Webopedia.

AOL Instant Messenger
Home page for AOL's Instant Messenger (AIM) system. You can download the free AIM software from here.

Choosing an Instant Messaging System
A series of articles covering the fundamentals of enterprise instant messaging and what you need to know as an IT decision-maker.

Instant Messaging Can Usher in Instant Problems
IT managers are being warned that IM is fast becoming a gateway for more attacks on the corporate network.

Instant Messaging Planet
Complete coverage of the business opportunities emerging from IM including case studies, security updates, and infrastructure issues.

Instant Messaging Server Overview
Fuzzy on the fundamentals of IM? This overview explains the pros and cons of taking what was initially designed as a personal app and implementing it across the enterprise.

Yahoo! Messenger
Home page for Yahoo!'s instant messaging system called Yahoo! Messenger. You can download the free software from here.