jsTrace is a pure JavaScript library that enables you to set separate "switch levels" on various components within your JavaScript code in order to facilitate debugging without all the "noise" of debugging information you don't want to see at the moment
It is available as a NuGet Package and has an ASP.NET MVC companion package to help with server-side integration
More documentation at http://tommck.github.io/jstrace
NOTE: This project was previously hosted at codeplex and has been moved here.