HTTP Compression in IIS 5 Sucks, But Is Fixable
This is probably going to be a foreign language to most of the folks here, but I'm throwing it out there anyway, and mostly for my bookmarks.
I've been experimenting with adding gzip compression to reduce browser load times across some of the sites I maintain. I've had it enabled on Bend Blogs dynamic pages forever, as it's built into Gregarius (working on compression and consolidating some other content on there as well to reduce lookups). I've enabled it on this site, as well as my office's site on most pages (some didn't do too well with it for reasons I'll look into later, so I had to do it on a per-page basis with ob_gzhandler instead of on a site-wide Apache basis like I did here).
The one thing I was having trouble was figuring out how to do it on Internet Information Server 5 (IIS5 in Windows 2000). We have an online booking server here in the office that runs IIS5 (can't be upgraded to IIS6 easily -- tried once, blew things up, not doing it again). The directions here didn't do anything. Was glad I wasn't the only one that had trouble. Thankfully, I was directed to FlatCompression, which enables easy ISAPI filtering to enable compression on IIS5. Considering that the online booking software our business has to use is already slow (no fault of mine), anything to help speed up downloads is always good.
So if you're still stuck running an IIS5 server, do yourself a favor and get FlatCompression installed and test here and here to make sure it's sending gzip/zlib/compressed content properly.