Half Life/Portal - Wiki

The Half-Life universe, also known as the Half-Life and Portal universe, is a science fiction universe created by Valve Corporation in 1998, with the release of the video game Half-Life on the PC platform. It is told through four related story arcs, each stemming from a game: Half-Life, Half-Life 2, Portal, and Portal 2.
Half-Life has spawned since then many modifications, expansions, and sequels, most of which set in the same universe. Most of them were developed by Valve; however, Half-Life's three expansions, Blue Shift, Opposing Force and Decay were developed by Gearbox Software.

In 2005, Electronic Arts took over distribution of the Half-Life series.

Since its first installment, the series has been introduced to many consoles such as the PlayStation 2, PlayStation 3, and Xbox 360, as well as Mac. Starting on the GoldSrc engine, a modified Quake engine, the series now runs on the Source engine.

The protagonist of the Half-Life series is Gordon Freeman, a former Black Mesa employee whose attempt to escape from Black Mesa ends up in his employment by the G-Man. In the canon expansions and spin-offs, the featured playable characters are not Gordon Freeman, but rather a HECU Corporal and a security guard, both as eager as Gordon to make their way out.

In the spin-off series, including Portal and its sequel, Portal 2, the main protagonist, Chell, a Test Subject, is detained in the Aperture Science computer-aided Enrichment Center, run by the A.I. GLaDOS, the series' main antagonist.

The Black Mesa's trailer :