Wayne Berry and the crew at XCache Technologies is still kicking, with their interesting mix of software and hardware HTTP compression solutions.
The software is designed for IIS/ISA, while the hardware is a front-end for Web servers.
I had a chance to meet Wayne a few years ago, and was impressed by his dedication to Web performance. He also encouraged me to write some of the articles that you see at WebPerformance.ORG.
Check them out if you are looking for an IIS compression solution.

Disclaimer:
I am not paid or compensated in any way to promote the products of XCache Technologies.