Steam Crowbar Collective (the team behind the excellent “Black Mesa” HL1 remake) is teasing a new project

[Krvavi Abadas]

this is highly likely to be a new original game rather than another remake, as staff there have expressed interest in doing so.
the trailer also explicitly has a hidden message noting that it’s not Opposing Force, one of the three official Half-Life expansions.

 

[oldpuck]

Are they a commercial team? Is Black Mesa a commercial game?

 

[JazzyFuture]

Are they a commercial team? Is Black Mesa a commercial game?

Black Mesa is sold on Steam with permission from Valve, yes.