It is easy to implement and improve the overall performance of your web project.
The most unique Feature of that library is the System.Web.Handlers.AssemblyResourceLoader that load the WebResources was rewritten to enable compression and better performance, without making HTTP request each time WebResource need to be served.
2. Minify and compress css files.
3. Compress aspx pages.
4. Minify and compress WebResource.axd
6. Combine (automatically) css files and save them in cache or in file system
1. Easy to implement in existing project.
2. Every feature can be enabled or disables by configuration in Web.Config file.
3. All external files (js, css) and WebResources are been cached in client & server.
4. Time in the cache can be controlled in the Web.Config
5. Specified type of content can be exclude from the compression
6. Specified aspx files can be exclude from the compression
8. Frameworks 2.0, 3.0 & 3.5
9. The System.Web.Handlers.AssemblyResourceLoader that load the WebResources was rewritten to enable compression and better performance, and without making HTTP request each time WebResource need to be served.
10. Support IIS6 ans IIS7
Some technical info can find