Hi Bill, We tried to make a native Mac OS X version of Chimera two years ago but encountered many problems in the Tk windowing toolkit that Chimera uses. Chimera worked but these problems made it difficult to use (for example, windows could not be resized at times, places where 2 lines of text were to be shown, only showed the first line). I submitted about a dozen bug reports to the Tk developers. It appears that about half of those bugs have been fixed and it is probably time for us to try another native Mac build of Chimera. The coming two months we will be busy with an advisory meeting and a Chimera workshop. So we are not likely to work on a native Mac OS X Chimera for a few months. Tom