The Raspberry Pi is a $25 Linux-based computer that went for sale on Monday in the U.S. through Allied Electronics. However, the Raspberry Pi sold out in just a few hours. The A-version of the Pi costs $25 with specs that include 256MB RAM, one USB 2.0 socket, HDMI input, SD card input, and a 3.5 audio jack. The B-version costs $35 and is also out of stock at Allied Electronics. Specs of the B-vision are 512MB of RAM, two USB 2.0 ports, and an Ethernet port. The A-version does not have Ethernet. The A and B versions of the computers are about the size of a credit card.