In a move that’s sure to make Apple shake its fist and gnash its teeth, everybody’s favorite underdog, Psystar, has thrown legal caution to the wind and released the Open(3) Computer, starting at $599 without monitor, keyboard, or mouse.

The base configuration consists of “a mild-mannered desktop” but can be configured to a “powerhouse” thanks to CPU, RAM, and graphics upgrades.

Starting specs include:

• Mac OS X Leopard v10.5
• 2.8GHz Core2Duo E7400 CPU
• 2GB of DDR2 800 RAM
• 500GB SATA hard drive (7200 RPM)
• 20X DVD burner
• 256MB GeForce 8400GS graphics

You’ll need to add your own keyboard, mouse, and monitor along with whichever other upgrades tickle your fancy, but $599 is a pretty decent price.

Open(3) with Mac OS X [Psystar via Pocket-lint]