Blizzard's seminal 1998 strategy game StarCraft [official site] and its expansion, Brood War, are now free for all and sundry. The game that birthed modern digital sports! The game that launched a thousand zerg rushes! The game that still has the best tanks in all RTSland! Blizzard have updated StarCraft a touch to play nicer with modern computers but mostly it's still just StarCraft ("just StarCraft" she says!). The real overhaul is coming later this summer in the not-free StarCraft Remastered. But for now, free StarCraft for all is just dandy, ta.
You can grab StarCraft free for Windows here and for Mac here. Or grab 'em later. They're free indefinitely, not for a short window. Playing online requires you to sign up for a Battle.net account but the singleplayer and LAN play don't even need that.
The 1.18 patch notes mention changes like adding windowed fullscreen mode and an Observer mode while improving networking, the anticheat, and compatibility with new versions of Windows. Poking my head into the sorts of musty dens where grizzled StarCrafters swig rotgut and gob into spacespitoons, I do hear a bit of grumbling about others issues left unfixed. Hey, it's only 19 years old - give 'em time!
StarCraft Remastered, the versions Blizzard will charge for, are coming this summer with new high-res art, remastered audio, support for modern resolutions (and widescreen!), and so on. Have a peek in this announcement trailer from March: