Top PROGRAMMING GitHub Repositories & Tools (2026)

Open-source AI pair programming for desktop: a Mentor + Executor agent cross-check each other's code to catch AI hallucinations. Works with Claude Code, Codex, Gemini & opencode. macOS / Windows / Linux.

DOMjudge programming contest jury system

:gem: Feel++: Finite Element Embedded Language and Library in C++

JNI Bind is a set of advanced syntactic sugar for writing efficient correct JNI Code in C++20 and up (or C++17 with clang).

A programming language for libraries translated to all the others

A programming language that is higher level than Rust but lower level than Go. Someday, anyways.

Programming language and toolkit to create Warcraft III Maps

💎 The Missing Cheatsheet for Ruby

The open source Solver AI for Java and Kotlin to optimize scheduling and routing. Solve the vehicle routing problem, employee rostering, task assignment, maintenance scheduling and other planning problems.

CasADi is a symbolic framework for numeric optimization implementing automatic differentiation in forward and reverse modes on sparse matrix-valued computational graphs. It supports self-contained C-code generation and interfaces state-of-the-art codes such as SUNDIALS, IPOPT etc. It can be used from C++, Python, Matlab/Octave, Julia or Javascript

The Antimony programming language

Code for Java upgrade workshop

Test case generation framework for competitive programming problems

Self-hosted functional language with explicit effects. Compiles to JVM bytecode, C, and NVIDIA GPU kernels via cuTile.

The Slate programming language

cx is a C-family systems programming language for game development and high-performance software: data-oriented, productive, no GC, compiles to native code via LLVM/C.

Process Multiple Asynchronous Tasks in Various Ways - One at a time / Batched / Rate limited / Concurrently

MimIR is my Intermediate Representation

The Go/XGo Interpreter

A cross-platform 2D game engine with its own programming language and IDE.