First off thanks to the numerous people that reminded me that GZIP is a 'G' word - don't know how I missed this one when I was compiling my list for the Acceleration ABCs.

GZIP is a common technique used for compression of web traffic.  HTTP 1.1 compliant browsers send an Accept-Encoding header in requests indicating that they are able to receive compressed content.  Files that benefit from GZIP compression are text based files such as HTML, CSS, JS, and word documents just to name a few.  File size reductions typically range between 60 and 80%.  Compression of files provides benefits in both end user response times as well as a reduction in bandwidth used.  Additional infrastructure benefits can be achieved if the process intensive function is off-loaded to an application delivery controller.

F5 includes compression with Local Traffic Manager via the Intelligent Compression Module and WebAccelerator.  For more information on GZIP and compression in general check out The BIG-IP System with Intelligent Compression: Cutting Application Delivery Time and Optimizing Bandwidth.