It was obviously made in SDK, but yes.
Know what? Custom maps through the Steam Workshop may just be the new thing.
I realize it's quality is too good to have been made with the Map Editor
Which reminds me, the Map Editor doesn't let you use props, scenery, decals, crushers, change lighting, and other stuff, i understand it's for people who don't know how to use Hammer, but it severely limits you in designs and scenery, you can only make normal Aperture themed chambers, not Cave Johnson themed, not broken/environmentally overrun Aperture
I don't mind them making it simple, but i wish they could've added in tabs so you could choose from things like props, scenery, testing items, and be able to edit more things like the music that plays in your chamber, music that plays with active laser receivers/relays, when using an Aerial Faith Plate, things like that
I get you can edit the map in Hammer and add in the stuff there, but i mean that it'd just be nice to have more to add into your chambers without having to use Hammer