When would I want to use httpZip instead of IIS 6.0 built-in compression and ZipEnable?
In general, you should use the integrated compression functionality built into IIS 6.0 on Windows Server 2003 for compression, safely deployed and managed by ZipEnable. However, there are some important cases in which you will not be able to get the job done with IIS 6.0’s native compression engine — and where you should use httpZip and ISAPI-based compression on IIS 6.0: • Controlling compression timing collisions with other ISAPI filters or DLLs: You cannot adjust when IIS 6.0 built-in compression takes place in the request/response life cycle. As such, you may have a third party ISAPI filter operating on a request that collides with IIS 6.0 native compression to produce a broken or uncompressed page. Alternatively, as an ISAPI filter, the timing of httpZip compression can be adjusted (in IIS Manager, Properties, ISAPI Filters) to correct this issue. This will affect you if you are running Akamai’s Content Distribution Network (CDN), any ISAPI filters such as third party URL rewrite
