Valve is working on a new, secret game, and it sounds like Portal 3

Portal 2 - PC : Video Games

Portal prequel mod brings stunning RTX visuals to Valve's classic

Portal With RTX Explored: Legendary Valve Classic Gets A Gorgeous Ray Traced Makeover

13 years on Portal: Revolution has reminded me I'm still an idiot

Portal 2 - Wikipedia

Thinking Without Portals – How The Portal 2 Gel Mod Aperture Tag Came To Exist - Game Informer

Massive 'Portal 2' Expansion Coming This Fall, Thanks to Modding Community

Freewheeling Valve churns out big video-game bucks despite some growing pains

Portal Reloaded on Steam

Valve is working on a new, secret game, and it sounds like Portal 3

Portal 3 will have a pretty awesome starting point, if it ever gets made

Portal With RTX Explored: Legendary Valve Classic Gets A Gorgeous Ray Traced Makeover

The Portal movie is still alive, according to producer JJ Abrams