Hope this is the right section for this, since it isn't really a plug-in release per se, but since it's an alternative version of one of Unity's built in plug-ins, it seemed best to put it here.

If you've upgraded to Unity 4.3.x, and discovered you like most of it, but absolutely hate MonoDevelop 4, the new built-in script editor, it can be replaced.

Option 1: Re-install an old version of Unity (such as 4.2.2 if you still have it), copy the Monodevelop folder from this installation somewhere else, re-install Unity 4.3, and tell it to use the old version of MonoDevelop as an external editor.

Option 2: Since I've already done all that, you can just download this zipped copy of MonoDevelop 2.8.2, taken from Unity 4.2.2, and use it.

Either replace the version that shipped with Unity 4.3, or copy the old version to your program files folder as a standalone app, so that future Unity upgrades don't replace it. This is probably a good idea anyway, as it preserves the original shipped editor if you ever want to go back to it.

Link(s):
http://www72.zippyshare.com/v/15591492/file.html
Cheers, and Happy New Year to all.

Copypasta from: http://forum.cgpersia.com/f79/unity3d-4-3-revert-old-version-monodevelop-editor-86310/#ixzz2omyO7TcJ