If you're looking for "Alt-Tab" style window switching on OS X, the best thing I've found is Witch (http://manytricks.com/witch/ http://manytricks.com/witch/)

If you're looking for "Alt-Tab" style window switching on OS X, the best thing I've found is Witch (http://manytricks.com/witch/ http://manytricks.com/witch/) "Alt-Tab" switches between windows in the order you last focused each window, so it's ideally suited to a stack-based workflow where you may have many windows open but are only using a few of them. OS X already has "Command-Tab", but that switches between applications, not windows.