HTTP Profiler (httprof) is a simple program that summarizes packet traces of HTTP traffic, to highlight performance problems caused by excessive network traffic.
Many web sites and applications cost more than they should, due to unoptimized network behavior.
The original goal of httprof was to help people understand that, of all the costs their application incurs, the cost of TLS or SSL (HTTPS) is relatively low. However, it is useful for network profiling generally.
The code is now available via SVN, and as a zip file (see the left-hand side of this page for featured downloads). I have tested it on FreeBSD 7 (Python 2.5), Windows 7 (Python 2.6), and Ubuntu 9 (Python 2.6). It "should" work on Mac OS X, too.
The conference slides are also available: http://httprof.googlecode.com/files/http-profiling-web-2.0-expo-2009.pdf
Here is a screenshot of part of a report generated by httprof: