UnIDE is an IDE designed specifically for the Unity game engine. It features everything you would expect from an IDE, and its built right into the Unity editor UI.
UnIDE has advanced Intellisense style auto complete and tooltips for C# and Unityscript, and generic auto completion for all other files, including Boo and shaders.
Quickly track down and fix errors, warnings, and logs with the Unity console integration.
Find and replace things quickly with dynamic highlighting of search terms. Other occurrences of your current text selection are also highlighted.
Customize how UnIDE looks and performs with many settings including fonts and themes.
Includes a powerful plugin system to allow easy extensibility. Auto Complete, Error Tracking, and Find/Replace are all implemented as plugins.