This is a great little piece of freeware, but it falls short of the gold standard in maintenance apps: Cocktail. Onyx returns cryptic error messages to me from time to time, while Cocktail has never missed a beat. Nevertheless, I recommend Onyx as a free solution to scheduled maintenance, and most users probably won't notice the ever so slight bugginess of Onyx.

I do have one major problem with Onyx: The installer package. No stand-alone application like Onyx should ever come in a package that needs to run Apple's installer - this defeats the whole purpose of application packages! Onyx should be a drag and drop application on a disk image, so the user knows what's installed where. I am forced to strongly question the bona fides of a developer who would add such needless complexity to his app distribution.

Ditch the installer package, and I give it five stars - until then, I'm going to detract points for extreme user unfriendliness.