Open Source Projects using CSS
A curated collection of the 629 best open source software using CSS. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.
Organize and secure your documents in one central hub
Stars
5,571Last commit
1 day agoLicense
AGPL-3.0
A document management platform that helps you archive, organize, and search files with email ingestion, tagging capabilities, and powerful search functionality.
Open Source Alternative to:
Automated translations that scale with your code and commits
Stars
5,398Last commit
1 day agoLicense
Apache-2.0
Transform your app into a global product with AI-powered localization that integrates directly into your development workflow. Supports 83+ languages with Git-native automation.
Open Source Alternative to:
Virtual office platform for engaging remote collaboration
Stars
5,870Last commit
1 day agoLicense
Unknown
Create customizable virtual workspaces for remote teams to interact naturally, host events, and collaborate through spontaneous conversations and scheduled meetings.
Open Source Alternative to:
Open-source BI for modern data teams
Stars
6,195Last commit
9 hours agoLicense
MIT
Self-serve analytics platform that transforms dbt models into interactive dashboards, enabling data-driven decisions across organizations.
Open Source Alternative to:
Self-hosted cloud platform with automated security
Stars
6,188Last commit
11 days agoLicense
Unknown
Complete self-hosting solution with automated maintenance, Smart-Shield protection, anti-DDoS, SSO authentication, and VPN access for secure private cloud management.
Open Source Alternative to:
Self-hosted group chat without recurring subscription fees
Stars
Stars growing over the last 30 days4,791Last commit
18 hours agoLicense
MIT
Install your own group chat system with @mentions, DMs, and mobile support. One-time purchase, no monthly fees. Includes full source code for customization.
Open Source Alternative to:
The open-source, affordable email platform
Stars
5,529Last commit
2 days agoLicense
AGPL-3.0
Plunk unifies marketing, transactional, and broadcast emails into a single, complete solution for businesses of all sizes.
Open Source Alternative to:
Intercept, modify, and debug HTTP(S) requests effortlessly
Stars
6,754Last commit
1 day agoLicense
AGPL-3.0
A powerful browser extension and desktop app for developers to manipulate network requests, debug APIs, and improve web app testing
Open Source Alternative to:
Enterprise monitoring for networks, apps, and infrastructure
Stars
6,485Last commit
9 hours 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:
Feature flags and remote config for rapid deployment
Stars
6,603Last commit
17 hours agoLicense
BSD-3-Clause
Powerful feature management platform for seamless software releases, A/B testing, and personalized user experiences.
Open Source Alternative to:
Smart desktop AI assistant with powerful local knowledge features
Stars
5,372Last commit
1 month agoLicense
Unknown
Cross-platform desktop AI assistant supporting multiple providers, local knowledge base, and custom prompts. Integrates MCP protocol for enhanced AI tool capabilities.
Open Source Alternative to:
Clean your system and free disk space
Stars
Stars growing over the last 30 days7,178Last commit
20 hours agoLicense
GPL-3.0
BleachBit frees disk space & protects privacy by deleting cache, cookies, history & temp files from Firefox, Chrome & more. Open source for Linux/Windows.
Open Source Alternative to:
Secure, scalable API key management for developers
Stars
5,469Last commit
9 hours agoLicense
AGPL-3.0
Streamline API authentication with UnKey's powerful, developer-friendly platform for creating, revoking, and monitoring API keys.
Open Source Alternative to:
Distributed OLAP database for real-time analytics at scale
Stars
6,161Last commit
9 hours agoLicense
Apache-2.0
Sub-second SQL queries on fresh streaming data at petabyte scale, built for high-concurrency user-facing apps and AI agent backends.
Open Source Alternative to:
Free, cross-platform video editor that's easy to learn
Stars
6,662Last commit
12 hours agoLicense
GPL-3.0
A free, open-source video editor for Linux, Mac, and Windows with animation, effects, multi-track editing, and 3D title rendering.
Open Source Alternative to:
Secure, encrypted notes for your digital life
Stars
6,672Last commit
4 days agoLicense
AGPL-3.0
Cross-platform note-taking app with end-to-end encryption, offline access, and powerful organization features for privacy-conscious users.
Open Source Alternative to:
Continuous web-based localization for global reach
Stars
6,114Last commit
10 hours agoLicense
GPL-3.0
Web-based continuous localization platform with version control integration, quality checks, and clean interface. Used by 2,500+ projects in 165+ countries.
Open Source Alternative to:
Effortless event-driven workflows for modern applications
Stars
5,964Last commit
9 hours agoLicense
SSPL-1.0
Simplify backend processes with event-driven functions, seamless integrations, and powerful debugging tools for developers.
Open Source Alternative to:
Build, automate, and improve AI agents with your team
Stars
4,846Last commit
10 hours agoLicense
MIT
Open-source workspace for building and running AI agents: chat-driven development, scheduling, human-in-the-loop approvals, versioning, and tracing. Self-host or use the cloud.
Open Source Alternative to:
Professional image editing without the price tag
Stars
6,535Last commit
12 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:
Deploy a professional status page in minutes, no coding required
Stars
5,211Last commit
1 day agoLicense
MIT
Free, open-source status page and uptime monitor with Docker deployment. Track 11 service types, manage incidents, schedule maintenance, and notify subscribers instantly.
Open Source Alternative to:
Pay per email sent, not for contact storage
Stars
4,744Last commit
2 days agoLicense
AGPL-3.0
Open source email platform for transactional and marketing emails. Self-host or use cloud service with transparent pricing - pay only for emails sent.
Open Source Alternative to:
Full observability for AI agents in production
Stars
4,728Last commit
23 hours agoLicense
MIT
Open-source platform for monitoring AI agents: captures traces, surfaces failure patterns, alerts on issues, and helps you verify fixes with automated evals.
Open Source Alternative to:
Secure password management for teams
Stars
6,179Last commit
1 day agoLicense
AGPL-3.0
Open source password manager focused on security, collaboration and privacy for organizations
Open Source Alternative to:
Simulation-based testing and evaluation for AI agents
Stars
4,983Last commit
9 hours agoLicense
Apache-2.0
Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence.
Open Source Alternative to:
Open-source CRM that puts simplicity and control first
Stars
Stars growing over the last 30 days3,827Last commit
9 hours agoLicense
AGPL-3.0
A flexible and customizable CRM platform for managing contacts, deals, and customer relationships without the complexity or user-based pricing of traditional solutions.
Open Source Alternative to:
Powerful helpdesk solution for streamlined customer service
Stars
6,019Last commit
9 hours agoLicense
AGPL-3.0
Zammad is an open-source helpdesk software that centralizes customer communications and helps deliver great service experiences efficiently.
Open Source Alternative to:
Flexible eCommerce platform for brands that stand out
Stars
5,344Last commit
16 hours agoLicense
BSD-3-Clause
Open-source eCommerce platform offering customization, scalability and enterprise-grade features for brands of all sizes
Open Source Alternative to:
Open source modular logistics platform for faster app development
Stars
Stars growing quickly over the last 30 days4,369Last commit
11 hours agoLicense
AGPL-3.0
Fleetbase is a comprehensive open source logistics suite offering API, TMS, driver and customer apps for streamlined operations and development.
Open Source Alternative to:
Enterprise workplace AI with data you own and control
Stars
3,842Last commit
9 hours agoLicense
Apache-2.0
Self-hostable enterprise AI platform that unifies business data across apps, powers a knowledge graph for cited answers, and lets teams build AI agents across their stack.
Open Source Alternative to:
Navigate anywhere with detailed offline maps and GPS
Stars
6,097Last commit
9 hours agoLicense
Unknown
Comprehensive offline navigation app with detailed maps, turn-by-turn guidance, and specialized routing for hiking, cycling, and walking worldwide.
Open Source Alternative to:
Spreadsheet-like interface for PostgreSQL databases
Stars
5,157Last commit
18 hours agoLicense
GPL-3.0
A self-hosted tool that provides an intuitive, spreadsheet-style interface for viewing, editing, and querying PostgreSQL databases without technical expertise.
Open Source Alternative to:
Effortlessly manage events and sell tickets online
Stars
4,072Last commit
21 hours agoLicense
Unknown
Hi.Events is a comprehensive platform for event management and online ticket sales, offering features like QR code check-in, custom ticket types, and embeddable widgets.
Open Source Alternative to:
Powerful observability made simple for developers
Stars
4,518Last commit
9 hours agoLicense
MIT
Logfire offers intuitive observability tools for Python applications, combining logs, profiling, and telemetry in one platform.
Open Source Alternative to:
Stateful AI agents that remember, learn, and improve over time
Stars
Stars growing over the last 30 days3,660Last commit
10 hours agoLicense
Apache-2.0
Build persistent AI agents with continuous memory, scheduled tasks, and multi-channel communication via Slack, Discord, and Telegram, using your own API keys.
Open Source Alternative to:
Effortless time tracking for teams and projects
Stars
5,084Last commit
13 hours agoLicense
AGPL-3.0
Open-source time tracking solution for businesses of all sizes. Manage projects, track billable hours, and generate insightful reports.
Open Source Alternative to:
Effortless group scheduling for seamless collaboration
Stars
5,310Last commit
10 hours agoLicense
AGPL-3.0
A user-friendly, open-source tool for coordinating events and meetings without the hassle of back-and-forth emails or messages.
Open Source Alternative to:
Open-source data integration for modern stacks
Stars
5,108Last commit
13 hours agoLicense
MIT
Collect, transform, and sync data across your entire infrastructure with a flexible, code-based approach to data integration.
Open Source Alternative to:
Build reliable AI agents with unified tool integration
Stars
4,917Last commit
5 months agoLicense
Apache-2.0
Platform for connecting AI agents to 500+ tools with built-in multi-tenant auth management and granular permissions using either function calling or a unified MCP server
Open Source Alternative to:
Self-hosted team workspace with chat, docs, and databases
Stars
5,171Last commit
7 months agoLicense
Apache-2.0
Local-first collaboration platform combining real-time chat, rich text pages, databases, and file management in a single self-hostable workspace.
Open Source Alternative to:
Build powerful websites with the open-source CMS
Stars
4,292Last commit
21 hours agoLicense
GPL-2.0
A flexible and extensible content management system for creating dynamic websites and digital experiences
Open Source Alternative to:
Craft flexible, powerful websites with ease
Stars
4,909Last commit
21 hours agoLicense
Unknown
A flat-file CMS that combines simplicity and flexibility, empowering developers to build custom websites without database complexity.
Open Source Alternative to:
Capture – Capture screenshots, generate PDFs, scrape content, extract metadata, and automate browsers with one API.
Docmost
Capture
CodeRabbit