GZIP format is developed by GNU Project and standardized by IETF in RFC 1952, which MUST be considered by web developers to improve their websites' performance, there are several Quintessential articles documented using gzip compression, they are:

10 Tips for Writing High-Performance Web Applications
Best Practices for Speeding Up Your Web Site
How To Optimize Your Site With GZIP Compression
IIS 7 Compression. Good? Bad? How much?

A gzip compressed HTTP package can significantly save bandwidth thus speed up browser rendering after use hitting enter, so that user experience got improved finally, nowadays most of the popular browsers such as IE, Firefox, Chrome, Opera support gzip encoded content (please refer: http://en.wikipedia.org/wiki/HTTP_compression).

PS: the other compression encoding is deflate, "but it's less effective and less popular" (refer: http://developer.yahoo.com/performance/rules.html). Yahoo uses gzip compression and suggest developers do that:

 

Compression in IIS

For ASP.NET developer who host website。。。