Portal is a series of first-person puzzle-platform video games developed by Valve. Set in the Half-Life universe, the two main games in the series, Portal (2007) and Portal 2 (2011), center on a woman, Chell, forced to undergo a series of tests within the Aperture Science Enrichment Center by a malicious artificial intelligence, GLaDOS (Genetic Lifeform and Disk Operating System), that controls the facility.