While fans wonder if Valve will ever continue the Half-Life series, you can download an expanded version of long-in-development fan remake of the original, Black Mesa, right now.
Technically, though, it's still not done yet! Black Mesa is now available in Early Access for $US20.
You can still totally download an older version of the mod for free. Nothing has changed there.
Why $US20, then?
"In addition, our ambitions go beyond the original Xen chapters found in Half-Life. We have a standard of quality that we have to achieve. Early Access allows us to commit resources to bring you the remaining chapters with the quality that you expect."
Yep, Xen still sucks. I would pay for someone to fix it. For now, here's what you get:
Heavily updated single player experience — The Black Mesa single player experience has greatly improved from the mod release; new visuals, new voice over, updated gameplay encounters, stability changes and more. Xen is not part of the Steam release of Black Mesa, but will included as a free update when it is ready. Black Mesa Multiplayer — Fight with or against your friends, in two game modes across six iconic maps from the Half-Life Deathmatch universe: Bounce, Gasworks, Lambdabunker, Stalkyard, Subtransit and Undertow. Custom Modding Tools — Use the same tools the developers used to create your own mods, modes and maps for Black Mesa and Black Mesa Multiplayer … Fully integrated Workshop — … and then share your work on the fully integrated workshop! Complete Steam Integration — Collect trading cards, backgrounds, emoticons, achievements, and everything else you would expect out of a Steam integrated game.
As for the singleplayer stuff, the team thinks they're most of the way there:
"We currently have the first ~85% of our single player campaign completed. For the last 15% we want to not only recreate it, but improve upon it to make it an enjoyable and memorable experience. We feel it will take us considerable time to get the last 15% up to our standards, and putting a time estimate on it would be a total guess."
Black Mesa costs $US20 now, but the price might go up, as development heads to the finish line.