Pintos is an instructional operating system create at Stanford University by Ben Pfaff in 2004. Pintos originated as a replacement for Nachos, a similar system originally developed at UC Berkeley by Tom Anderson, and was designed along similar lines. Like Nachos, Pintos is intended to introduce undergraduates to concepts in operating system design and implementation by requiring them to implement significant portions of a real operating system, including thread and memory management and file system access.