Play the Half-Life Series for Free

Steam News announces that anyone with a free Steam account can play all the games in the Half-Life series for free between now and the release of Half-Life: Alyx in March. Here's word:
Series FREE to play for Steam users, from now until the day it launches!

If you already have Steam installed, you can click the following links to start playing now!
Half-Life
Half-Life 2
Half-Life 2: Episode One
Half-Life 2: Episode Two

If you don't have Steam, you can download it here.

Half-Life: Alyx is set before the events of Half-Life 2 and the episodes, but the games share characters and story elements. The Half-Life: Alyx team believes that the best way to enjoy the new game is to play through the old ones, especially Half-Life 2 and the episodes, so we want to make that as easy as possible.