If you are looking for a version of StarCraft with updated visuals you might want to wait for StarCraft Remastered that is coming this summer. If you are looking for a modern build of the classic game with a streamlined interface that works incredibly well on modern systems for free you should check this out. Many of the old problems with classic StarCraft have been fixed, like needing to tunnel ports to enable classic Battle.net play and Blizzard also removed some strange networking options for multiplayer no one uses (like serial connections). The game is presented in 4x3 and the games original low res art(by modern standards) is kept but doesn't seem to mess up your desktop by putting your computer in 640x480 resolution. It's a nice touch and makes the whole new game build experience really solid and fresh. Blizzard also wrapped the whole new StarCraft install process in a fancy new theme that looks a lot like their modern Battle.net client. It's sad that StarCraft doesn't show up in the modern Battle.net client but one reason why this might not happen is that classic Battle.net games aren't compatible with newer Battle.net and don't have features like cross game chat and the like. That or Blizzard is saving a spot in the new Battle.net client for StarCraft remastered. Not sure which but at some point it might be nice to get all classic Blizzard games in the modern client.
The classic StarCraft game we all love is present and both StarCraft and Brood War campaigns are there for you to play... for free. I really like that Blizzard is giving out the original StarCraft for free and if you want the updated Remastered edition you can get that and both versions will be compatible with each other in terms of multiplayer. I appreciate companies giving these classic games a fresh coat of paint and when they release them for free it's like an early Christmas present.
You can download StarCraft on Windows using the link below:
You can download StarCraft for Mac using the link below:
If you want to delve a bit deeper into the history of StarCraft development, Blizzard has a very interesting retrospective article you can read below.