Two things that persistently hold a special place in geek hearts are the Apple II desktop computer and the video game Portal. What happens when you put them together? Magic.
Vince Weaver, an assistant professor at the University of Maine's Electrical & Computer Engineering department, has very generously created a version of the beloved game using Applesoft BASIC. He uploaded a video of his game in action to YouTube and I think this guy's my new favourite vlogger.
If you're unfamiliar with Portal, it's a puzzle-platforming game in which a player opens one portal as an entrance and one as an exit. The player has to teleport themselves or objects through the portals to solve various dilemmas. It's also well known for its excellent sense of humour which remains intact with this Apple II crossover. The cake is still a lie and a beautiful end credits sequence plays Johnathon Coulton's song "Still Alive."
Weaver has made his work available on his site and the game can be played on an Apple II, a downloadable emulator or through an in browser emulator. He also has a couple of other delightful projects worth checking out.