Nightly builds for Mac OS X.
I no longer compile nightly builds for Mac OS X, mainly because now Tclkit is stable and up to date runtimes are easy to find.
So where to go now?
For up-to-date Tclkits for Mac OS X you should have a look at Roy Keene's Wiki (made with KitCreator).
Pat Thoyts provides Tclkits for Windows, Linux, Android and Solaris (made with kitgen).
And if you have a valid ActiveState license, you can use their base-tk (made with their own magic tools).