There is no need to compile anything since the whole program is just a Python script. Just run it, and that's all.
Ultrasol requires Python 1.5.2 and Tcl/Tk 8.0.5 or better. Both packages are freely available for Unix, Windows and Macintosh platforms.
Ultrasol is free Open Source software distributed under the terms of the GNU GPL.
If you want to modify the Ultrasol source code or write your own Python programs you can get the development system from http://www.python.org/download/download_windows.html
Also, installable packages exist for all major Linux distributions, FreeBSD and HPUX.
As I don't have access to a Mac I'd appreciate any detailed feedback on installation and look & feel. "Porting" from X11 to Windows only required some minor changes in the default font settings, so I hope the situation on Macs is similar.