This is a plugin for Eclipse that turns it into a Maya IDE.  As it is Python-centric, it also requires the pyDev plugin.  Features include:

• Send the entire contents of an editor to Maya
• Send a highlighted selection to Maya
• Get results back from Maya in it's own console view
• Anything done within Maya's own script editor is also echoed in the console view
• Change the port number of the socket at any time
• Open up documentation for Maya's Python API, Python Commands, Pymel and WPF

For more info, see tutorial here:

http://highend3d.com/maya/tutorials/using_tools_scripts/Using-Eclipse-as-a-Maya-IDE-367.html