If you aren't familiar with Half-Life, it was developed by Valve (creator of Steam) and it was an immensely popular first person shooter series set in a very speculative universe.  The first game came out in 1998, with the latest release back in 2007.  For years, there have been rumors of a Half-Life 3, and it looks like it could be happening thanks to a possible benchmark for the HTC Vive Virtual Reality Headset. 

According to VG 24/7, HTC recently released a benchmark tool to users in order to see if their PC can handle what would be required to run the $799 Vive virtual reality headset, developed by Valve with HTC.  This tool is built on Valve's Source Engine, and some of the files that could have been tied to Half-Life 3 found their way to it, as well as Left 4 Dead 3.  Left 4 Dead is an FPS game series set in a zombie plague, and it was also a hit for the company.  This has also given rise to Left 4 Dead 3 rumors. 

So far, the possibility of any direct connection to what has been found in the Source engine files and what games Valve are developing has not been established.  Part of the reason why fans of the Half-Life franchise are so excited is that there is a connection, albeit a faint one, to Half-Life 3 and HTC Vive.  This means that the next version of Half-Life could be played in virtual reality.  According to The News Independent, users saw Half-Life 3 in a short demo which was released and then pulled back by Valve.

The most proof of Half-Life 3 in the demo was that of a pet robot dog named Alyx Vance, one of the characters of the Half-Life series.  The dog is an improvement over what was in previous versions of the game, which shows that someone has been working on improving the game. 

The issue is that fans truly want a Half-Life 3 as a final episode Half-Life 2: Episode Three, was scheduled to appear around Christmas 2007, but it never did.  Oddly enough, there was a game that debuted that year set in the same universe with Portal.  Portal is a puzzle-solving game that was popular enough for a sequel, Portal 2, released in 2011. 

A recent conversation with game developers on PC Gamer has revealed that Valve should do more now that they have created a huge amount of cash thanks to the money they have made on Steam.  Valve could do a whole lot and take a lot of risks as well, and give players a really great story.