They say the best things in life are free, and for UNIX computers, open source software certainly goes a long way towards proving that statement. KStars, a planetarium program written for UNIX machines running the K Desktop Environment, has been ported to OS X via Fink and X11, and offers Mac users a sophisticated but free planetarium program. Neale Monks takes a closer look at KStars and sees how it stacks against the shareware and commercial Mac OS planetarium programs. Not directly an OS news item, but definately of general interest especially for our geek readers. At the end of the article, you will find links to five more reviews of astronomy applications for the Mac.