It's worth mentioning that in a pinch, Audacity (which is free) can do a pretty good noiseprint noise removal, too.

You have to fiddle with the parameters, as it's a tradeoff between removing more noise and impinging on the wanted signal, but it's surprisingly good. I have used it to rescue quite a lot of rushes from shoots where the environment doesn't behave.

It's probably not as good as Izotope, but it's a great deal better than the bog standard attempts to notch filter that a lot of people use.