Open Source Projects using CSS
A curated collection of the 580 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.
Petabyte-scale observability, without the massive bill.
Stars
21,354Last commit
10 hours agoLicense
AGPL-3.0
Monitor logs, metrics, and traces with an open-source observability platform. Achieve petabyte scale with 140x lower storage costs and high performance.
Open Source Alternative to:
Self-hosted newsletter and mailing list manager
Stars
23,015Last commit
1 day agoLicense
AGPL-3.0
Send email campaigns and transactional messages to millions of subscribers with a single high-performance binary backed by Postgres.
Open Source Alternative to:
Python-native workflow orchestration for data and ML teams
Stars
23,649Last commit
14 hours agoLicense
Apache-2.0
Orchestrate data pipelines, ML jobs, and agent workflows in plain Python with automatic retries, scheduling, and a unified UI for every run across your infrastructure.
Open Source Alternative to:
Cross-platform terminal with AI built in
Stars
22,074Last commit
9 days agoLicense
Apache-2.0
Enhance your terminal with AI, file previews, and web browsing. Available on MacOS, Linux, and Windows.
Open Source Alternative to:
Modern and intuitive SQL client for multiple databases
Stars
23,478Last commit
11 hours agoLicense
Unknown
A user-friendly SQL editor and database manager supporting MySQL, PostgreSQL, SQLite, SQL Server and more with full feature parity across operating systems.
Open Source Alternative to:
Watch YouTube without Google tracking you or showing ads
Stars
22,700Last commit
4 days agoLicense
AGPL-3.0
Open source front-end for YouTube that strips out ads, tracking, and algorithmic distractions while letting you subscribe to channels and manage playlists.
Open Source Alternative to:
Self-hosted personal finance manager with double-entry bookkeeping
Stars
24,378Last commit
16 hours agoLicense
AGPL-3.0
Track transactions, budgets, and accounts with a double-entry system, multi-currency support, rule engine, and REST API. Fully self-hostable.
Open Source Alternative to:
Fast, private browser that puts you first
Stars
23,384Last commit
11 hours agoLicense
MPL-2.0
A secure web browser that blocks ads and trackers, protects privacy, and loads pages faster while saving data and battery life.
Open Source Alternative to:
Fast, secure, offline API client with Git integration
Stars
19,095Last commit
11 hours agoLicense
MIT
A modern API client offering local-only data storage, Git integration, plugin extensibility, and multi-protocol support for developers.
Open Source Alternative to:
Build AI agents and RPA workflows without writing code
Stars
21,574Last commit
6 months agoLicense
Unknown
No-code platform for building AI agents and RPA workflows that automate repetitive business tasks across finance, HR, sales, and operations.
Open Source Alternative to:
Self-hosted music streaming for your personal collection
Stars
22,991Last commit
12 hours agoLicense
GPL-3.0
Open source music server that streams your personal library via a web player or any Subsonic-compatible mobile app on iOS and Android.
Open Source Alternative to:
Social media reimagined for community and connection
Stars
18,234Last commit
11 hours agoLicense
MIT
A decentralized social network focused on fostering meaningful interactions and giving users control over their data and experience.
Open Source Alternative to:
Unify data models and metrics across your entire stack
Stars
20,671Last commit
10 hours agoLicense
Unknown
Cube is a universal semantic layer that connects data sources to analytics tools, providing consistent definitions and fast queries.
Open Source Alternative to:
No-code web scraping, crawling, and extraction platform
Stars
17,228Last commit
2 days agoLicense
AGPL-3.0
Turn any website into structured data using a visual recorder, natural language prompts, or API. Includes proxy rotation, scheduling, and webhook integrations.
Open Source Alternative to:
Task manager built for deep work, privacy, and focus
Stars
21,476Last commit
3 days agoLicense
MIT
Combines task management, time tracking, Pomodoro focus sessions, and GitHub/Jira integration in a local-first app for Windows, macOS, Linux, Android, and iOS.
Open Source Alternative to:
Collaborative bookmark manager for teams and individuals
Stars
19,533Last commit
9 hours agoLicense
AGPL-3.0
Open-source platform to collect, organize, and preserve webpages with powerful collaboration features
Open Source Alternative to:
Free, private screen recording for Chrome
Stars
18,491Last commit
2 days agoLicense
GPL-3.0
Capture, annotate, and edit screen recordings with no limits or sign-up required. Completely private and open source.
Open Source Alternative to:
Visual project management with complete data control
Stars
21,059Last commit
2 days agoLicense
MIT
Open-source Kanban board solution offering visual task management, self-hosting capabilities, and robust security features for teams and individuals.
Open Source Alternative to:
Empower your digital strategy with actionable insights
Stars
21,794Last commit
11 hours agoLicense
GPL-3.0
Comprehensive web analytics platform offering full data ownership, privacy protection, and customizable insights for data-driven decision making.
Open Source Alternative to:
Privacy-first knowledge base with any AI model you choose
Stars
15,977Last commit
1 day agoLicense
Apache-2.0
Self-hostable NotebookLM alternative that lets teams build searchable knowledge bases from diverse sources, with support for any LLM and no data limits.
Open Source Alternative to:
Scalable open-source distributed storage system
Stars
16,948Last commit
10 hours agoLicense
Unknown
Ceph provides unified object, block, and file storage from a single cluster built on commodity hardware.
Open Source Alternative to:
Create, edit and share documents with real-time collaboration
Stars
16,738Last commit
12 hours agoLicense
MIT
Transform document collaboration with real-time editing, version control, and secure sharing features that enhance team productivity and communication.
Open Source Alternative to:
Open-source mail server with unlimited sending & AI tools
Stars
15,429Last commit
2 months agoLicense
AGPL-3.0
Self-hosted email marketing platform with unlimited sending, AI-powered email creation, real-time analytics, and no monthly fees. Complete SMTP solution.
Open Source Alternative to:
Open-source workflow automation for developers
Stars
17,591Last commit
9 hours agoLicense
Unknown
Powerful, self-hosted platform for building and running workflows, scripts, and apps with code-first approach and collaborative features.
Open Source Alternative to:
Secure password management for individuals and businesses
Stars
19,904Last commit
9 hours agoLicense
Unknown
Bitwarden is an open source password manager that securely stores, shares, and autofills passwords across unlimited devices.
Open Source Alternative to:
Secure, open-source document signing for everyone
Stars
14,634Last commit
11 hours agoLicense
AGPL-3.0
Streamline your document workflows with a powerful, privacy-focused e-signature platform that puts you in control of your data.
Open Source Alternative to:
Run dozens of AI coding agents in parallel on your machine
Stars
13,152Last commit
9 hours agoLicense
Elastic-2.0
macOS app that orchestrates multiple AI coding agents simultaneously, each in its own isolated Git worktree, so you can work on many tasks at once.
Open Source Alternative to:
Run long-running AI tasks without timeouts or servers
Stars
16,077Last commit
10 hours agoLicense
Apache-2.0
Open source TypeScript platform for building and deploying AI agents and background workflows with retries, queues, observability, and elastic scaling.
Open Source Alternative to:
SQLite-compatible database for scalable multi-tenant applications
Stars
17,149Last commit
9 days agoLicense
MIT
Turso provides a simple developer experience with SQLite compatibility, allowing you to build and scale multi-tenant applications with unlimited databases.
Open Source Alternative to:
Ad-free music player that streams from multiple sources
Stars
18,305Last commit
5 days agoLicense
AGPL-3.0
Open-source desktop music player for Windows, macOS, and Linux. Search artists and tracks across multiple sources, build playlists, and listen without ads or tracking.
Open Source Alternative to:
Open-source Q&A platform for knowledge sharing
Stars
15,654Last commit
4 days agoLicense
Apache-2.0
A versatile, community-driven Q&A platform that fosters collaboration and knowledge exchange within organizations and communities.
Open Source Alternative to:
Open-source API documentation and testing platform
Stars
15,949Last commit
10 hours agoLicense
MIT
Scalar is an open-source tool for building, customizing, and hosting interactive API documentation with OpenAPI support.
Open Source Alternative to:
Open source headless commerce with REST API, no platform fees, built for B2B and marketplaces
Stars
15,632Last commit
10 hours agoLicense
BSD-3-Clause
Headless eCommerce platform with REST API, TypeScript SDK, and Next.js storefront. Handle B2B, multi-vendor marketplaces, and cross-border commerce. Self-hosted, open source, zero fees.
Open Source Alternative to:
Professional audio editing made simple and free
Stars
17,609Last commit
2 days agoLicense
Unknown
Free, open-source audio editor and recorder for all platforms. Record, edit, mix and enhance audio with professional tools. Perfect for music, podcasts, and more.
Open Source Alternative to:
Open-source ecommerce platform for WordPress
Stars
10,462Last commit
10 hours agoLicense
GPL-2.0
Build and manage online stores with customizable features, extensions, and themes for businesses of all sizes.
Open Source Alternative to:
Streamline your business finances and operations
Stars
14,780Last commit
2 months agoLicense
AGPL-3.0
All-in-one tool for freelancers and small businesses to manage finances, track time, store files, and send invoices efficiently.
Open Source Alternative to:
Fast grammar checking that respects your privacy
Stars
14,628Last commit
10 hours agoLicense
Apache-2.0
Open source grammar checker that analyzes your writing quickly while keeping your data completely private and secure on your device.
Open Source Alternative to:
Understand your audience with privacy-first analytics.
Stars
12,812Last commit
9 hours agoLicense
AGPL-3.0
Get next-gen, open-source, and cookieless web analytics. Understand user behavior with session replays, real-time data, and web vitals. GDPR/CCPA compliant.
Open Source Alternative to:
Privacy-first survey and experience management platform
Stars
12,795Last commit
10 hours agoLicense
AGPL-3.0
Collect feedback across websites, apps, and emails with targeted surveys, user segmentation, and GDPR-compliant data handling. Self-host or use the cloud.
Open Source Alternative to:
Classic, agile, or hybrid project management, self-hosted
Stars
15,899Last commit
10 hours agoLicense
GPL-3.0
Full-featured project management platform with Gantt charts, agile boards, time tracking, and team collaboration. Self-host or use managed cloud hosting.
Open Source Alternative to:
Secure, seamless authentication for modern applications
Stars
14,398Last commit
15 hours agoLicense
MPL-2.0
An open-source identity solution offering customizable login experiences, multi-tenant support, and comprehensive user management.
Open Source Alternative to:
Secure, customizable identity infrastructure for developers
Stars
14,799Last commit
15 hours agoLicense
AGPL-3.0
ZITADEL provides a comprehensive identity management solution with easy APIs, customizable workflows, and serverless deployment options.
Open Source Alternative to:
c15t – Open-source cookie banner, built for control and lightening fast modern web apps.
c15t
Sent
InfluxDB