Microsoft's Eric Lawrence, Security Program Manager for Internet Explorer and developer of the freeware web debugging platform, Fiddler, describes the origins of the tool, how it is used at Microsoft, and how it can be extended to bring value to virtually any situation requiring analysis of HTTP or HTTPS traffic.

Lawrence provides an overview of Fiddler's architecture, demonstrates its native support for both HTTP and HTTPS traffic and explains how the application can be used to modify the data stream between the web server and application client.

Additionally, he describes how to use the tool for first-order performance measurement, session baselining, and shows how to extend the scope of Fiddler through scripting.

The Fiddler toolkit includes other useful utilities including FiddlerCap, a simple capture applet designed to allow end-users to capture and store their traffic for later analysis by developers, and Meddler, an extremely light-weight, general purpose HTTP server.