The Professional VEX Toolchain.
PROS is a lightweight, fast, open-source OS for the VEX V5 Brain — built and maintained by Purdue ACM SIGBots since 2011. 306 stars, 33 releases, latest v4.2.2.
PROS by the Numbers
Real numbers from the purduesigbots GitHub org.
A Lightweight, Fast Open-Source OS for VEX V5
PROS (Purdue Robotics Operating System) is a "lightweight and fast alternative open source operating system for the VEX V5 Brain," developed and maintained by students at Purdue University through Purdue ACM SIGBots. Development began in 2011 and the project has been continuously updated ever since.
PROS supports full C23 and C++23 with GNU extensions via the GCC toolchain, runs bare metal on the V5 Brain, and ships with OkapiLib for motion control. The latest release is v4.2.2 (February 2026). Licensed under MPL-2.0 (kernel) and BSD-3-Clause (binaries).
#include "pros/pros.hpp"
// Drive motors
pros::Motor left_drive(1, pros::E_MOTOR_GEARSET_18);
pros::Motor right_drive(2, pros::E_MOTOR_GEARSET_18, true);
void autonomous() {
left_drive.move_relative(300, 200);
right_drive.move_relative(300, 200);
pros::delay(1500);
}Everything You Need to Compete
PROS includes every tool a competitive VEX team needs to go from zero to world-class.
Full C/C++ Development
Write real embedded C/C++ for VEX V5 and EXP brains. No wrappers, no limitations — use the language the way professionals do.
FreeRTOS Based
PROS runs on FreeRTOS, giving teams access to proper multitasking, scheduling, and real-time control — the same OS used in industry.
PROS Package Manager
Manage libraries and templates with the built-in package manager. Share code across your organization or publish open-source libraries.
VS Code Extension
First-class VS Code support with IntelliSense, build tasks, device management, and serial terminal — all in one extension.
Comprehensive Docs
Detailed API documentation, tutorials, and guides covering everything from getting started to advanced PID and odometry implementations.
Fully Open Source
Every line of PROS is open source under an MIT-compatible license. Inspect, modify, contribute, or build your own tools on top.
Built at Purdue. Shared with the World.
PROS is entirely designed, built, and maintained by current and former SIGBots members. Copyright 2011–2023 Purdue ACM SIGBots.
The core OS kernel for VEX V5. C23/C++23 via GCC, bare metal execution, 33 releases, latest v4.2.2.
The most-forked VEX library on GitHub. Chassis controllers, motion profiling, filtering, and unit types.
Official VS Code extension (TypeScript, MPL-2.0) for project management, flashing, and serial terminal.
Cross-platform Python CLI for project creation, building, uploading, and serial terminal access.
Open-source knowledge base for VEX competitors. Covers hardware, software, electronics, CAD, and strategy.
An advanced odometry and motion control library for PROS, with 6 forks and active community development.
Start Building with PROS
Everything you need to get started, from installation to advanced motion control.
Want to Contribute to PROS?
PROS is built by the community, for the community. Whether you're fixing bugs or adding features, contributions are always welcome.