Mac (9734 programs)

Pros: Unobtrusive. Can be tweaked.

Cons: Very basic.

Pros: Run up to 5 versions simultaneously.

Cons: You'll need to provide all the versions to try.

Pros: Easy to quit or kill an app.

Cons: Search isn't always effective. Feels a little counter-intuitive.

Pros: Five colors to pick from. Double click and lock.

Cons: Basic features.