Black Mesa took its time getting Xen right. The Half-Life overhaul notoriously spent the better part of the 2010s trying to nail the original's divisive final chapters—and now, you can retrace those steps with an official "Xen Museum" workshop mod.
Containing over 56 maps and framed around a Jurassic Park-style main lobby, the Xen Museum tracks over 5 years of experimentation and iteration on Half-Life's borderworld. The hub itself contains a gallery of unused and previously-unseen assets, but the real exhibition lies in the museum's three wings.
Divided into hubs representing Xen's three chapters (Xen, Gonarch, and Interloper), the museum contains dozens of work-in-progress maps, each with sever, representing various stages of development. There are often multiple editions of each level, letting you walk through Xen as it goes from a barren, toxic green wasteland to the overgrown, thriving dimension-between-dimensions we finally ended up with.
"We hope you enjoy this fun and interactive tour of our intensely difficult 5 years of development," the Black Mesa team wrote on Steam. "We thought this was a really cool and unique way to show off the way a game can develop and evolve over time. We've never quite seen anything like it, and we hope you guys have as much of a blast playing it as we did making it!"
It's a fitting way to cap off a mod that's been a constant presence in the Half-Life community for over 15 years. Last November, Crowbar Collective finally closed the book on Black Mesa with a 1.5 "Definitive Edition" update—though other modders have already begun using that foundation to start remastering Half-Life's Blue Shift expansion.