The finishing line for Crowbar Collective and their re-imaging of Half-Life with Black Mesa is almost in sight, with a preview of the full finished game to come soon. In a new announcement on Steam, they said it will be available to test as soon as it's ready.
Plenty of upgrades are still going in though, like an overhaul to the HECU AI so the soldiers you encounter around Black Mesa on cleanup duty will be a lot smarter. They now know to "lay down suppressing fire, flank your position, communicate more, throw grenades more effectively, use their MP5 grenade launchers, and more" which has me quite excited to see in action.
You can also see some graphical upgrades done on the Earth section with these examples:
Some areas have been adjusted too, the combat areas in particular so they can "better utilize the AI". Using everything their team learned when building the Xen section. They said they've been watching people play, to identify where "the pace came to a grinding halt" and redid those parts.
They also confirmed, again, that another update will come post-release they're jokingly calling Black Mesa: Definitive Edition with fixes to rough spots and more polish on the artwork, as well as continue to improve other parts like Steam Workshop support. Something else that sounds good, is they want to document how to best use the Source Engine to "help others get information and solve problems".
You can find Black Mesa on Steam.