In the latest DOTA 2 update there is a new text file called hl3.txt, which inside makes mention of ziplines, squads, citizens, NPCs and VR. Naturally when this was discovered it led certain portions of the internet to completely lose their shit thinking that it was a clue to Half-Life 3 actually coming out.
The actual files in question are located here and as noted by the SteamDB include:
“npc.quest/citizen” “If you want your citizens to squad with the player but not obey commands the player gives to move the squad, put a concept here and this citizen will speak the concept instead of obeying the order.”
“vrchaperone” and “vrmovement”
No clue telling if these files are something Half-Life 3 related or not, we can only speculate. They could be an accident, hoax, old, a new leak, etc.
I guess this keeps the Half-Life 3 dream alive for fans of the series.