All Half-Life games “FREE” until ‘Alyx’ launches in March, dev AMA tomorrow on Reddit

This afternoon, the official Valve Twitter channel lit up with special news (including a Q&A time tomorrow to “answer ‘some’ questions” with the development of the game).
The games that will be free to play (not own) are;
Half-Life
Half-Life: Opposing Force
Half-Life: Blue Shift
Team Fortress (1)
Half-Life 2
Half-Life 2: Episode 1
Half-Life 2: Episode 2