The differences between IDA Pro, ImmDBG and OllyDBG

Security Aegis: "In this blog post we will look at some of the differences between a several of the most widely used Debuggers/Disassemblers. This post is by no means exhaustive. It is meant as a brief overview to give people new to reversing a “quick start” guide. "

http://www.securityaegis.com/new-to-reversing-the-differences-between-ida-pro-immdbg-and-ollydbg/