Are Zunes just restricted to the Zune Marketplace?

No, don’t worry, I’m not using a Zune. I’m happy with iPods. I dislike Zunes. So is the only program you can use to sync music with your Zune the Zune Marketplace? I keep hearing criticisms of Apple’s iPod, saying that they’re restricted to iTunes only, which is annoying to me, because iTunes is the best online music store, and besides, you can get any CD you want and put it on there too.

So are you able to use anything other than Zune Marketplace with Zunes?