Testing for 343 industries' remastered Halo 3 is rolling out to PC "in the first half of next month".
In a new community update, 343i's Postums said the closed Halo 3 testing will permit the team to test its distribution pipeline, test updates to Challenges, gather feedback on the content, and "ensure all supporting systems are functioning properly in preparation for bringing Halo 3 to Halo: The Master Chief Collection on PC".
"Halo 3 is the next game in our lineup making its way to PC," wrote "Postums" (thanks, RPS). "In 2007, it was the Halo title that brought us Theater, Forge, and some of the community's most beloved gametypes like Grifball, Infection, and many more. Halo 3 holds a special place in many player's hearts and we know it's one of, if not THE most anticipated titles in the collection. In good news, public flighting for Halo 3 PC is on the horizon!"
That test will include multiplayer modes across 10 maps - including Custom Games, Social Games, and Competitive Games - and five campaign missions; Sierra 117, The Storm, The Ark, The Covenant, and Halo. Forge mode and Theatre will also be available.
"If you aren't a Halo Insider already, please head on over here and register," Postums added. "If it's been a while since you have visited your Halo Insider profile, please take some time to make sure everything is up to date with your profile including your PC specs (many folks have been upgrading their machines during quarantine so please make sure your profile is current!). Ensuring you are up-to-date and registered with a valid (and verified!) email, greatly improves your chances of being selected for flights."
For more information and to find out how you can be in with a chance of getting involved, head on over to the update post.
Microsoft previously announced that Halo 3: ODST (Campaign) and Halo 4 would complete the Master Chief Collection on PC before the end of the year.