IISxpress uses an opt-out compression model in contrast to the opt-in model used by the built in IIS compression. This results in easy compression configuration since all responses are candidates for compression and do not need to be explicitly included by editing the metabase.
Of course IISxpress allows you to control what responses are compressed. To achieve this you configure a set of exclusion rules which allow you to prevent compression based on the extension of the request (e.g. JPG/GIF/PNG), the content type of the response (e.g. image/jpeg, image/png), the location of the requested data in your web server directory tree (e.g. http://mysite.com/images) or even by the IP address of the client. All this configuration grunt work can be a performed with a set of user friendly wizards, alternately sit back and let IISxpress work out what should be comrpressed.
IISxpress tracks the effectiveness of compression on each response, if the data in the response did not compress well (maybe it even got bigger) then IISxpress will not compress it again. Over time IISxpress will exclude the low gain responses from compression leaving only the responses where a good gain is achieved.
So, by simply installing IISxpress you can compress ASP.NET, ASP, CGI and pretty much any kind of dynamic content you wish.
To see IISxpress compressing a rich ASP.NET application (Community Server) you should check out our demo videos:
IISxpress 2.0 Short Demonstration Video
IISxpress 2.0 Demonstration Video