Earlier this week the Duke Nukem 3D: Megaton edition was updated with the level editor, Steam Workshop support and a guide explaining how it all works. AND LO, the mapmakers did come, and make a wide and varied collection of Duke levels for us to download and play for free while making happy nostalgic noises to ourselves.
There are 75 available already, many of which are redistributions of classic fan-made Duke maps. The collection brings the efforts of prolific back into Steam's wide limelight, so think of it as an awesome little museum full of perfectly playable and entertaining levels. Beyond the Steam Workshop you'll find thousands more on sites like the Duke Repository .
Duke Nukem 3D is also on sale on Steam at 75% off to celebrate its arrival on the Steam Workshop, and it'll be that price until December 16.