The recently released Vive benchmark tool contains some references to Half-Life 3 and Left 4 Dead 3, kick-starting another round of speculation.
source
With the announcement of the Vive’s $800 price tag, Valve released a handy benchmark tool you can use to see if your PC is up to the task.
This tool is built on Valve’s Source Engine, and naturally, some files that could be tied to Left 4 Dead 3 and Half-Life 3 have found their way into it.
Valve News Network compiled all the included mentions and how they relate to earlier findings about the two mysterious games.
This is mere speculation, of course, as there was never any direct connection between what’s found in Source Engine files and games that’re actually in development.
source