Open Source C++ Projects
C++ is a general-purpose programming language used to build software that needs control over performance, memory, and hardware resources. It supports applications ranging from operating systems and desktop programs to games, databases, and machine-learning tools. Its combination of low-level capabilities and abstractions makes it suitable for both resource-constrained environments and large, complex codebases, though it can require careful management of memory and dependencies.
Open source C++ software includes libraries, development frameworks, command-line utilities, and complete desktop or server applications. When evaluating a project, consider its license, release history, maintenance activity, documentation, supported platforms, compiler requirements, and compatibility with your existing stack. C++ tools can serve application developers, researchers, system programmers, and organizations building software that must run efficiently across different devices or operating systems.
49 repositories · updated October 3, 2026
agent.cpp: Build Local AI Agents in C++
agent.cpp is a C++ library for building agents that run small language models locally through llama.cpp. It provides an agent loop, tools, callbacks, and support for GGUF models, grammar constraints, and LoRA adapters.
ACM-ICPC-Algorithms: Competitive Programming Algorithms
A collection of algorithms and data structures for competitive programming, organized by topic. It is useful for ICPC participants and programmers looking for reference implementations across common contest problems.
awesome-competitive-programming: Find Contest Learning Resources
A curated directory of resources for competitive programming, algorithms, and data structures. Use it to find study materials, practice platforms, contest tools, and communities in one place.
CompetitiveCode: Explore Competitive Programming Problems and Solutions
CompetitiveCode is a community collection of interesting programming challenges and documented solutions organized by source or topic. It is useful for learners practicing algorithms and contributors sharing solutions in several programming languages.
helium: A Privacy-Focused Chromium Web Browser
Helium is a Chromium-based browser focused on privacy, unbiased ad-blocking, and a simpler browsing experience. It is aimed at people who want Chromium compatibility without extra browser clutter.
xgrammar: Constrain Language Model Output to Structured Formats
XGrammar is a library for constrained decoding that helps language models produce outputs matching JSON, regular expressions, or context-free grammars. It suits teams integrating structured output into LLM inference and applications that need reliable machine-readable responses.
notes: Organize and Write Markdown Notes
Notes is a cross-platform desktop app for writing and organizing private Markdown notes. It combines folders, tags, a Kanban view for tasks, and a keyboard-focused editor for people who want a local note-taking workflow.
PYAS: Layered Endpoint Security for Windows
PYAS is a Windows endpoint security application that combines local machine-learning and YARA scanning with real-time monitoring, optional cloud analysis, and kernel-level controls. It suits security researchers and Windows users evaluating layered protection, with driver and remediation features best tested in an isolated environment.
apkstudio: Decompile and Edit Android APKs
APK Studio is a Qt-based desktop IDE for inspecting and modifying Android application packages. It brings APK decompilation, code and resource viewing, rebuilding, signing, and installation into one cross-platform workflow.
vamp: Accelerate Robot Motion Planning with SIMD
VAMP is a C++ motion-planning library that uses CPU SIMD instructions to speed up collision checking and forward kinematics. It offers several sampling-based planners and Python bindings for robotics research and applications.
h264-mp4-encoder: Encode H.264 Video to MP4 in JavaScript
A WebAssembly-backed library for encoding RGBA or YUV frames into H.264 video in an MP4 container. It targets JavaScript applications in browsers or Node.js, including workflows that turn canvas frames into video.
FinceptTerminal: Research Markets with a Desktop Finance Terminal
FinceptTerminal is a native desktop application for financial research, combining market data, analytics, AI agents, and paper trading. It suits individual researchers and developers who can bring their own data and model credentials and accept the AGPL-3.0 license.