Open Source Projects using C++
A curated collection of the 80 best open source software using C++. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.
High-performance time-series database for massive data scale
Stars
17,449Last commit
8 hours agoLicense
Apache-2.0
Open-source time-series database offering massive ingestion throughput, millisecond queries, and SQL extensions, designed for optimal performance at any hardware scale.
Open Source Alternative to:
Advanced terminal with modern features for Mac developers
Stars
18,191Last commit
1 day agoLicense
GPL-2.0
Feature-rich terminal replacement for macOS with split panes, search, autocomplete, and extensive customization options for enhanced productivity.
Open Source Alternative to:
Free, open-source framework for cross-platform game development
Stars
14,545Last commit
8 days agoLicense
Unknown
Build games in C# that run on Windows, macOS, Linux, iOS, Android, and major consoles. No royalties, no subscriptions, no runtime fees.
Open Source Alternative to:
Self-hosted file sync with AI-powered organization
Stars
15,347Last commit
3 days agoLicense
Unknown
Open source file sync and sharing platform with custom properties, AI automation, collaborative editing, and enterprise-grade security for teams.
Open Source Alternative to:
A free, open source, cross-platform video editor
Stars
15,449Last commit
22 hours agoLicense
GPL-3.0
Free, open-source video editor supporting 4K resolution, hundreds of formats, and professional features like Blackmagic Design integration across Windows, Mac, and Linux.
Open Source Alternative to:
Type shortcuts, expand to full text instantly
Stars
14,654Last commit
2 days agoLicense
GPL-3.0
Cross-platform text expander that replaces typed keywords with full snippets, templates, dates, emojis, or script output across any app.
Open Source Alternative to:
Collect, organize, cite, and share research in one place
Stars
15,662Last commit
4 days agoLicense
Unknown
Reference manager that captures sources from the web, organizes them with tags and collections, and generates citations in 9,000+ styles for Word, LibreOffice, and Google Docs.
Open Source Alternative to:
Professional RAW photo editing and workflow management
Stars
13,293Last commit
14 hours agoLicense
GPL-3.0
Open source photography workflow application for RAW development. Non-destructive editing, professional color management, and GPU acceleration for photographers.
Open Source Alternative to:
High-performance distributed database for all workloads
Stars
10,340Last commit
10 days agoLicense
Apache-2.0
Scalable, high-availability database system supporting OLTP, OLAP, and hybrid transactional/analytical processing workloads.
Open Source Alternative to:
Lightning-fast open source search engine for big data
Stars
12,062Last commit
21 hours agoLicense
GPL-3.0
Open source search database delivering 2.83x faster performance than Elasticsearch. Features vector search, SQL interface, and full-text capabilities.
Open Source Alternative to:
Professional digital painting made accessible to everyone
Stars
10,584Last commit
7 hours agoLicense
GPL-3.0
Free and open source painting program built by artists for artists. Features professional brushes, layers, animation tools, and drawing assistants for all skill levels.
Open Source Alternative to:
Simplify expense management for businesses of all sizes
Stars
5,066Last commit
6 hours agoLicense
MIT
Automate expense reporting, reimbursements, and corporate card management with real-time data sync and powerful integrations.
Visual app builder that integrates with your existing codebase
Stars
7,117Last commit
20 hours agoLicense
MIT
Open-source visual editor for building websites and web apps. Connect to any data source, design custom UIs, and ship production React code without leaving your stack.
Open Source Alternative to:
The tensor database for AI data
Stars
9,253Last commit
5 months agoLicense
Apache-2.0
Deep Lake is an open-source database for storing, querying and managing complex AI data like images, audio, and embeddings.
Open Source Alternative to:
Secure email, calendar and contacts with end-to-end encryption
Stars
8,019Last commit
2 days agoLicense
GPL-3.0
Tuta offers encrypted email, calendar and contacts with quantum-resistant security, protecting your privacy without ads or tracking.
Open Source Alternative to:
Time-series database built for industrial IoT workloads
Stars
6,420Last commit
7 hours agoLicense
Apache-2.0
Apache IoTDB manages industrial IoT time-series data with high-throughput read/write, edge-cloud sync, ultra-high compression, and integrations with Hadoop, Spark, Flink, and Grafana.
Open Source Alternative to:
Enterprise monitoring for networks, apps, and infrastructure
Stars
6,482Last commit
3 days agoLicense
AGPL-3.0
Monitors networks, servers, cloud services, IoT, and OT environments with no per-device licensing fees, available self-hosted or as a managed SaaS platform.
Open Source Alternative to:
Professional image editing without the price tag
Stars
6,529Last commit
10 hours agoLicense
Unknown
Free, open-source image editor with professional tools for photo manipulation, digital art creation, and graphic design. Cross-platform support.
Open Source Alternative to:
Professional video editing without the price tag
Stars
5,894Last commit
12 hours agoLicense
GPL-3.0
Cross-platform non-linear video editor offering professional features for free. Edit videos on Linux, Windows, macOS, and BSD with advanced tools and effects.
Open Source Alternative to:
Free office suite with Microsoft compatibility
Stars
4,533Last commit
7 hours agoLicense
GPL-3.0
Complete free office suite compatible with Microsoft formats (.doc, .docx, .xls, .xlsx, .ppt, .pptx). Open source alternative with regular updates.
Open Source Alternative to:
High-performance graph computing for scalable data analysis
Stars
4,622Last commit
8 hours agoLicense
Unknown
Memgraph is a scalable, in-memory graph database solution offering high-performance computing and Neo4j compatibility.
Open Source Alternative to:
Open-source document editing suite for secure collaboration
Stars
3,381Last commit
10 days agoLicense
Unknown
Powerful online document editor with Microsoft Office compatibility. Integrate into your infrastructure or use trusted hosting partners for secure team collaboration.
Open Source Alternative to:
Professional raw photo processing made free and powerful
Stars
4,237Last commit
7 hours agoLicense
GPL-3.0
Free, cross-platform raw image processor with 32-bit floating point engine, advanced demosaicing algorithms, and professional-grade editing tools for photographers.
Open Source Alternative to:
Transform any TV into professional digital signage
Stars
3,696Last commit
1 day agoLicense
Unknown
Free open-source digital signage software that turns Raspberry Pi or old PCs into powerful display solutions. Manage images, videos, and web content easily.
Open Source Alternative to:
Fast and beautiful launcher for quick access to apps and tools
Stars
3,176Last commit
5 days agoLicense
MIT
A modern macOS launcher that provides instant access to applications, utilities, and system functions through an elegant and efficient interface.
Open Source Alternative to:
Complete IT infrastructure monitoring made simple
Stars
2,599Last commit
15 hours agoLicense
GPL-2.0
Monitor your entire IT infrastructure with 2,000+ plugins, automated discovery, and scalable architecture. Open source and enterprise solutions available.
Open Source Alternative to:
Serverless team chat over Tor, no phone number needed
Stars
2,659Last commit
6 days agoLicense
GPL-3.0
Quiet is a peer-to-peer messaging app that syncs messages directly between devices over Tor, with no central server, no phone number required, and no metadata leaks.
Open Source Alternative to:
Real-time stream processing made simple and affordable
Stars
2,270Last commit
7 days agoLicense
Apache-2.0
Timeplus is a lightweight, powerful, and cost-efficient stream processing platform for real-time analytics, deployed as a single binary.
Open source monitoring for complex IT infrastructure
Stars
2,241Last commit
3 days agoLicense
GPL-3.0
Monitor networks, servers, and cloud environments with flexible open-source solution. Custom checks, fast alerts, and complete infrastructure control.
Open Source Alternative to:
Type 10x faster with AI-powered voice dictation
Stars
1,561Last commit
6 days agoLicense
MIT
Open source AI dictation app that transforms speech to text with context-aware formatting. Fast, accurate transcription for meetings, notes, and hands-free typing.
Open Source Alternative to:
Unlock Data's Potential with Open Source Power
Stars
1,433Last commit
11 hours agoLicense
Apache-2.0
Leverage advanced analytics with a modern PostgreSQL kernel. 100% open source for robust data solutions.
Open Source Alternative to:
Lightroom-compatible RAW editor, no subscription
Stars
1,217Last commit
6 hours agoLicense
MIT
Non-destructive RAW photo editor for macOS, Linux, and Windows that reads Lightroom catalogs, presets, and camera profiles. Free, MIT licensed, built in Rust.
Open Source Alternative to:
Dictate faster and control your Mac with voice
Stars
656Last commit
27 days agoLicense
MIT
Free, open-source macOS voice assistant that transcribes speech, applies AI transformations, and controls apps hands-free. No subscription, no training required.
Open Source Alternative to:
Fast, minimal VPN built on modern cryptography
Stars
729Last commit
6 months agoLicense
GPL-2.0
VPN protocol that runs inside the Linux kernel, using public-key cryptography to create encrypted tunnels across UDP with minimal configuration.
Open Source Alternative to:
Track games, movies, anime, manga, and books in one place
Stars
588Last commit
2 days agoLicense
MIT
Cross-platform collection manager for retro games, movies, TV shows, anime, manga, visual novels, and books with tier lists, visual boards, and import/export.
Open Source Alternative to:
Open-source AI browser for intelligent web automation
Stars
515Last commit
7 months agoLicense
BSD-3-Clause
Privacy-focused AI browser with intelligent agents for research, analysis, and workflow automation. Features unified memory, compliance guardrails, and seamless integrations.
Open Source Alternative to:
Fast, secure, and privacy-focused web browsing
Stars
407Last commit
1 day agoLicense
MPL-2.0
Midori Browser is a lightweight, fast, and secure browser that protects users' privacy, available for Windows, Linux, and Android.
Open Source Alternative to:
Transcribe meetings and voice notes with local AI, no bots required
Stars
115Last commit
15 days agoLicense
MIT
Free, open-source AI note-taker that transcribes meetings and voice notes locally using Whisper and Parakeet. Works on Mac, Windows, and mobile without invasive bots.
Open Source Alternative to:
c15t – Open-source cookie banner, built for control and lightening fast modern web apps.
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