Fiddler is an HTTP debugging proxy server application written by Eric Lawrence, formerly a Program Manager on the Internet Explorer development team at Microsoft.
Fiddler captures HTTP and HTTPS traffic and logs it for the user to review (the latter by implementing a man-in-the-middle interception using self-signed certificates).
On 6 October 2003, Eric Lawrence released the initial official version of Fiddler. On 12 September 2012, Eric Lawrence announced that Fiddler was acquired by Telerik and he would join the company to work on Fiddler on a full-time basis. On 23 December 2015, Eric Lawrence announced he was leaving Telerik in favor of Google’s Chrome security team. Telerik continues developing Fiddler now.