What are some alternatives?
When comparing Portal and 8start, you can also consider the following products
Antichamber - "A game with half of the attention to detail and imagination Antichamber has would be a smash hit - this bare-bones first-person puzzler is one of the most thought-provoking, engaging, and challenging video games ever developed.
PStart - PStart is a simple tray tool to start user defined applications.
Quantum Conundrum - Quantum Conundrum is a First-person Perspective game with strong Sci-fi, Puzzle-Platform, and Single-player elements published by Square Enix and developed by Airtight Games.
FramaKey - FramaKey is a package of portable and ready-to-use Free Software that can be carried on a USB key...
Proteus - Proteus - Proteus is a great electrical suite for circuit simulation purposes. You can simulate a single processor or multiple ones at the same time. The application is a great alternative for Virtual System Modelling.
PortableApps.com - PortableApps.com is a website offering many free, commonly used Windows applications that have been...