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

Details of Multiple Cancelled Valve Projects Revealed, Including Half-Life 3 : r/pcgaming

PS3 Cheats - Portal 2 Guide - IGN

Portal ARG, Half-Life Wiki

Biggest leak in Valve's history includes pretty much everything from Half-Life 2, Portal, and Team Fortress 2

Valve Launches Steam Link on Meta Quest to Connect to SteamVR

Valve Corporation - Wikipedia

I mean the new UI is decent : r/Steam

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

10 years of 'Portal 2': How Valve redefined video game secrets

Valve's Secret Weapon

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

Portal Writer Shares Theory About Why Valve Doesn't Do Threequels

Portal (video game, puzzle platformer, physics puzzle, science fiction, 3D platformer, comedy, first-person puzzler, robot) reviews & ratings - Glitchwave

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