This analysis includes statistics for either a single or all selected transactions, an auto-responder that will replay saved responses to specific requests, a tool for hand-constructing responses, filtering to exclude specific transactions, a very powerful event-driven scripting language, and a whole slew of content inspectors, which include a breakdown of the request header, a text-only view, a hexadecimal view, an analysis of authorizations used, a "raw" or uninterrupted view, and an XML interpretation.

There's also a timeline view, which is useful when filtering is used as the graphical entries are linked to the actual transactions they represent. This lets you jump from the timeline to the detailed analysis of any transaction.

are also available from both the author and third parties (the is well documented) and include custom inspectors to provide syntax highlighting for FiddlerScript (Fiddler's scripting language), HTML, Javascript and XML as well as a content blocker and an image gallery (this fetches and displays all images found in the selected transactions).

Fiddler is a gem of a tool. Well documented, well featured, extensible, and, above all, incredibly useful. I'll give Fiddler 5 out of 5.