Protothreads are extremely lightweight stackless threads designed for severely memory constrained systems.


  • Very small RAM overhead - only two bytes per protothread and no extra stacks
  • Highly portable - the protothreads library is 100% pure C and no architecture specific assembly code
  • Can be used with or without an OS
  • Provides blocking wait without full multi-threading or stack-switching
  • Freely available under a BSD-like open source license


License: BSD

Protothreads Platforms

  • AVR
  • 8051

Protothreads Components

  • None