The author of the scripts of Half-Life, Portal and Left 4 Dead, Chet Falisek, left Valve, where he worked for 12 years.
Falisek said that he parted with Valve on a friendly note.
“Nothing exciting or dramatic happened. I’ve given the company 12 years, worked on a lot of cool games. Now I wanted to change something. There are no ideas about what will happen next, but I will let you know when they appear,” wrote Chet Falisek, commenting on his departure.
In late 2016 and early 2017, Erik Wolpaw and Mark Laidlow, who worked on the scripts of the Half-Life series, Portal and other projects of the company, left Valve.
Source: Eurogamer