Is Guild Wars on Steam?

I'm curious, I've been hearing a lot about Guild Wars lately, and I'm wondering if it's available on Steam? I've been looking to dive into some new MMORPGs and this one has caught my eye. I know Steam has a vast library of games, so I figured I'd ask if this particular game is among them. If not, are there any similar games that I might enjoy that are available on Steam? I'm eager to hear your thoughts on this matter.