This is the script editor placed inside Unity.

Desc
- You can change your C#/Javascript/Boo scripts in a quick and easy way.
- No need to open MonoDevelop / Visual Studio to edit your codes.
- Just place 'QuickScriptEditor' window anywhere you want.
- Add/change/fix your scripts right away.


Features
- View / Edit / Save a script (C# / JavaScript / Boo )
- Manage font size/color and background color
- Keep saved history for each file


Link: Info