"MM" = Mighty Mouse.
I've never used the Cursor Editor. However, the Help page suggests tha some Windows XP cursors will need to be scaled down as far as the number of frames for use in OS X. I would therefore assume that the Editor will work in OS X, also. Whether it is easy to use, I have no idea. Yesterday, the "Get More Cursors" simply went to the old ResExcelence site which is transitioning to a paid site in conjunction with OS X Hints ( I think ). So it may be more difficult to import from those cursors right now. However, a Google might display several other places to import/download cursors. As for Cursor Editors, in general, I always go to VersionTracker, first. Recently, some one mentioned another site for finding apps.