gamersgate

It would normally have:

DRM:Steamworks (Requires a third-party download and account)

on the right hand side of the game's page if it activates on Steam.
You could just press Ctrl+F to search the page for "Steam" too to be sure.

Not all games sold on GamersGate activate on Steam, but many do.

Some games offer Steam key, others don't. Look where are the system requirements. There is written if it's drm free or Steam is required or it have other drm.

thank you very much for the fast answer :)

Some games will not be Steam DRM while others are. It will say whether it is Steam DRM on the products page.

Also, to be safe, always check the Steam filter when browsing for games.

Sorry to bring up back up an old post but I thought I would put this here rather than make a new post...
Would the current sale for Killing Floor
Give me a steam key or if it did not how would it work? , it says DRM is Steamworks which confuses me because I have no idea what that is