Halo 2 E3 2003 demo coming to Halo: The Master Chief Collection for PC as Steam Workshop mod on November 9

gematsu.com:

Publisher Xbox Game Studios and developer Halo Studios will release the Halo 2 demo showcased at E3 2003, which never made it into the final version of the game, for the PC (Steam) version of Halo: The Master Chief Collection as a free mod via Steam Workshop on November 9, the companies announced in celebration of the game’s 20th anniversary.

“The response to the demo at E3 was electric, and nearly every Halo fan remembers that demo and where they were when they were first blinded by its majesty,” said Halo community director Brian Jarrard. “Best of all, none of us ever would have expected that 20-plus years later, a group of passionate community modders would bring this demo to life as a full-fledged mission.”

While the E3 2003 demo was locked away for many years due to “several snags with technology,” the original assets and files were able to be recover thanks to the work of the Digsite data archaeology archive and valiant efforts from the wider Halo community. But the demo was built in a version of the Halo engine that no longer exists, and the assets were not compatible with any other existing versions of Halo 2.

“This put us in a bit of a quandary,” Halo senior franchise writer Kenneth Peters said. “Even the original executable is difficult to work with, as you need an Xbox developer kit to get it to boot, which is in increasingly short supply even within the studio. But now, in 2024, we have the Digsite-developed tools to analyze and automate up-porting old assets, and the unearthed knowledge to know why Bungie built things the way they did in the demo.”

Peters continued, “Steven Garcia (known to the community as General_101) was vital in getting this scenario stood up and even improved over the original. He was a one-man army and did a significant chunk of the work in developing tools, updating scripts, and even arting the levels. Digsite team members Ludus, Neo Te Aika, Sean T, xScruffyDaSasquatchx, and Killzone then provided finishing touches to replicate