NCrunch by Remco Mulder intelligently executes your .NET unit tests in background and displays test results in-line with your code in the Visual Studio editor. It saves you time to run tests manually and wait for their execution. It also gives you almost immediate feedback on code correctness as you type.

NCrunch fully supports most popular .NET unit testing frameworks like NUnit and MS Test. After the installation all you have to do is enable it for your solution via the NCrunch top level menu in Visual Studio. NCrunch will quickly execute your tests in background and display test results in-line with both tests and implementation code:

Passed test results in the Visual Studio 2010 editor

The current tests status is also displayed in the NCrunch Tests tool window:

NCrunch Tests tool window with the current tests status

The interesting part begins when you create a new test or change existing code. Just as you type, without explicitly saving your changes, NCrunch builds your code and re-runs tests. Designed with big projects in mind, NCrunch intelligently analyzes build dependencies, prioritizes tests execution order and uses asynchronous processes, additional processing cores, thread/process prioritization to minimize effects on Visual Studio IDE performance. Any test failures are immediately shown in the Visual Studio editor. Hovering over the error marker displays exception text:

Assertion failed exception description

NCrunch also collects code coverage information and marks lines not executed by unit tests by black dots. Code coverage also enables you to navigate to any covering tests from any line of code:

Black dots for lines not covered by tests

Context menu commands for a line of code covered by tests

Plus NCrunch measures tests execution time. For each line you can see its execution time and particularly slow lines are specially colored:

Execution time of the line of code

NCrunch is currently free of charge, supports Visual Studio 2008/2010/11 and NUnit/MS Test/Xunit/MbUnit/MSpec unit testing frameworks. You can download the latest installer from the official home page.