http://www.webpronews.com/expertarticles/2006/12/08/gzip-vs-deflate-compression-and-performance
http://www.stardeveloper.com/articles/display.html?article=2008111201&page=1
http://betterexplained.com/articles/how-to-optimize-your-site-with-gzip-compression/
on apache web servers
http://stackoverflow.com/questions/388595/why-use-deflate-instead-of-gzip-for-text-files-served-by-apache
http://httpd.apache.org/docs/2.0/mod/mod_deflate.html
http://www.orangecoat.com/smaller-and-faster-web-pages-with-gzip-deflate-and-apache
e.g. Gzip could be considered as a deprecated method, but it's worth to still use it by testing the content type
http://forums.devshed.com/apache-development-15/gzip-deflate-based-on-content-type-browser-446938.html