The core development team on Half-Life 3 includes some of Valve's most senior creators as well as a modder who built a Half-Life 2 spin-off, according to private information leaked online.
Late on Tuesday, Valve's project management system (based on the popular Jira service) was accessible to the public, due to what is suspected to be an internal human error. The files revealed that ten staff members make up the core Half-Life 3 development team, with an additional 46 people working on the project.
Valve has not once publicly discussed the Half-Life 3 project since it shipped Half-Life 2: Episode 2 in 2007, meaning the leaked management data is the first conclusive evidence of Valve's intentions with the long-awaited project.
Despite the frequency of Half-Life 3 hoaxes and misinformation, the Jira management system framework appears genuine, the emails of the staff are accurate, and the Valve Software domain name could not have been registered by a third-party.
Among the ten core Half-Life 3 developers is Adam Foster, once a hobbyist modder who built the popular Half-Life 2 mod, Minerva. Also in the team is Kelly Bailey, a sound designer, musician and game designer who has worked on all of the main Half-Life projects since the late '90s. Along with these is David Speyrer, a cabal lead (supervisor) on Half-Life 2 and Half-Life 2: Episode Two.
Experienced developers and designers, such as Jeff Lane and Jim Hughes, are also on the core team. However, the remainder are relatively new recruits, such as Jean Rochefort (Doom 3, Id software), Karl Whinnie (Left 4 Dead), Sergiy Migdalskiy (Portal 2) and Michael Coupland (Counter-Strike: Global Offensive).
It is also noted that Migdalskiy is a specialist in game optimisation for consoles, in particular Xbox 360 and PS3.
The tenth member is Ken Banks, who joined Valve in 2010 after working on projects such as Borderlands at Gearbox Software, who says he dreamed of becoming a game designer when he first played the original Half-Life in 1998.
On the extended team of 46 are distinguished Valve developers such as the writer Erik Wolpaw, Half-Life series level designer John Guthrie, Portal 2 key designer Josh Weier, senior Valve figurehead Ken Birdwell, and art director Ted Backman.
Valve managing director Gabe Newell has previously expressed a desire to not throw additional people onto projects and keep teams tight - a key reason just fifty developers are working on one of the most anticipated PC games in history.
The leak comes hours after it emerged that Valve has filed for trademark protection of the name Half-Life 3. Valve has said it will not discuss the project until it believes the time is right.
Update: The filing has since been removed and is thought to be an elaborate hoax.
In other developments, one NeoGAF user who accessed Valve's online management system, claims that 76 developers are working on the Left 4 Dead 3 project. Valve has not announced this project either, but a recent office photo unknowingly referenced it.