Can I get documentation snippets in addition to intellisense?

Can I get documentation snippets in addition to intellisense in MonoDevelop and Visual Studio?

Yes: http://www.unifycommunity.com/wiki/index.php?title=IDE_Documentation

HT: NCarter

See also: Documentation for UnityEngine.dll and UnityEditor.dll in the Wiki article Setting up Visual Studio for Unity (which also includes some more Mac related information).