In this article we are going to see the NUnit User Interface with its functionality. I am writing this for invoice person who are new for NUnit, spatially for new selenium webdriver user who run selenium tests with C#(VS2010) with NUnit.

NUnit is a open source unit test framework like as JUnit. NUnit can run any type of assembly either it is DLL or an EXE. NUnit can run the test functions that is written for NUnit. That means, the functions which takes the NUnit framework attributes, they can be recognize by NUnit. We can run NUnit with GUI or from command prompt. Lets start.
Step 1: Download latest NUnit from this link.
Step 2: See my this post for setting up NUnit Unit Test environment. (“Including Unit Test framework in the project “) this part.
Step 3: Run NUnit from start menu. We can see the GUI.
Step 4: Open an demo project(This is optional, I use an anonymous project, you can use my this code and build a DLL for NUnit)
After loading we can see a GUI like this.
Screen Shot 1
We can run NUnit with different Framework with different versions. 
Screen shot 2
We can open a saved NUnit project/a DLL or an EXE. 

Screen shot 3
We can run NUnit in mini GUI or Full GUI 
 Screen Shot4
We can change fonts, size , style for GUI and fixed are(result showing area) 
Screen Shot5
Screen Shot6 
We can add multiple Assembly(DLL/EXE/NUnit Project) with current project . This is important when ever any test case failed, we might need to test those failed test case associate assembly. 
Screen Shot7
All project are saved with some configuration. We can change the configurations . We can change the project settings also. 
Screen Shot8
We can partially run NUnit test cases
Screen Shot9.
We can check for assemblies, change the settings for GUI and Run Time.
Screen Shot10
We can see installed Addins. Some useful addin link from WIKI

…Thanks…... you may ask questions in comment.