Speed Up Your ASP.NET Web Site with Gzip Compression
I've used gzip compression on Apache/PHP projects before and the results are usually awesome. Especially for static files like CSS and Javascript files that compress to 30% of their original size.
Now that we're using ASP.NET and Umbraco so much these days I needed to figure out how to get gzip compression working in IIS. Apparently there was a major bug in IIS 5.0 and earlier, but if you are using IIS 6.0 and above you are in luck!
In fact, this was easy enough that if you have access to your windows server, you should do it for static files at the very least.
The methods to do this have been well documented so I will simply point you to those who have paved the way.
This is my favorite article on the subject. Love the visuals and the fact that it addresses all of the gotchas you may have along the way:
Asp.net & IIS Tricks:- Using GZip Compression with IIS 6.0 to compress your dynamic content such as your aspx pages and increase the client side experience by downloading the pages fast. - Smallworkarounds.net
Other articles on the subject:
IIS Compression in IIS6.0 - Scott Forsyth's Blog
HTTP Compression and IIS 6.0 - Coding Horror
There are some considerations as to whether to compress dynamic pages. If they are changing a lot, then it may not make a lot of sense because they would be constantly re-zipped and cached. Not great for performance. In that case, just zip the static files.