What is Valve corp. DLL?

Company Valve Corporation, commonly known as Valve, is an American video game developer and publisher based in Bellevue, Washington. Founded in 1996 by Michael Abrash, Gabe Newell, and Jay Wilbur, the company is renowned for its influential games such as Half-Life, Portal, and Dota 2, as well as its innovative business practices, particularly the introduction of digital distribution through Steam, a platform that has become one of the most widely used online marketplaces for video game sales. Valve's contributions extend beyond gaming into other areas like virtual reality with their VR headset, the Valve Index, which set new standards in the industry upon release.