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.
Lightweight distributed storage for self-hosting
Stars
Stars growing over the last 30 days4,736Last commit
4 days agoLicense
AGPL-3.0
Self-contained distributed object storage with S3 API compatibility. Runs on minimal hardware, replicates data across 3 zones for maximum resilience.
Open Source Alternative to:
A spreadsheet engine you can embed, self-host, or run in the browser
Stars
4,224Last commit
1 day agoLicense
Apache-2.0
IronCalc is an open-source, Rust-powered spreadsheet engine with .xlsx support, 300+ functions, and bindings for JavaScript and Python.
Open Source Alternative to:
Build powerful backends without leaving your browser
Stars
6,843Last commit
2 years agoLicense
Apache-2.0
A low-code platform for creating robust backends, complete with a spreadsheet UI for easy data management and custom functions.
Open Source Alternative to:
System-wide ad-blocking and privacy protection, no extensions needed
Stars
4,282Last commit
6 days agoLicense
MIT
Free, open-source desktop app that blocks ads, trackers, and surveillance scripts across all browsers and apps on Windows, macOS, and Linux.
Open Source Alternative to:
YAML-defined workflow orchestration, no database required
Stars
Stars growing over the last 30 days4,394Last commit
1 day agoLicense
GPL-3.0
Single-binary workflow orchestrator that runs scheduled DAGs locally or over SSH, with retries, human tasks, a built-in Web UI, and file-based state storage.
Open Source Alternative to:
Open-source growth platform for customer-centric teams
Stars
4,092Last commit
10 hours agoLicense
AGPL-3.0
All-in-one solution for marketing, sales, and customer service. Boost engagement, streamline workflows, and drive growth.
Open Source Alternative to:
Deploy apps instantly with git push - open source alternative
Stars
4,772Last commit
8 months agoLicense
MIT
Open source deployment platform that deploys apps directly from GitHub with zero-downtime, real-time logs, preview URLs, and support for Python, Node.js frameworks.
Open Source Alternative to:
Open source security automation platform for builders
Stars
3,846Last commit
14 hours agoLicense
AGPL-3.0
Tracecat is a scalable, self-hostable platform for automating security workflows and playbooks without limits.
Open Source Alternative to:
Secure, policy-based access control for modern applications
Stars
4,627Last commit
11 hours agoLicense
Apache-2.0
A scalable authorization layer that provides fine-grained access control through externalized policies, enabling secure and flexible permissions management.
Open Source Alternative to:
Feature-rich backend that runs anywhere you need it
Stars
3,774Last commit
26 days agoLicense
Apache-2.0
Lightweight Firebase alternative with database, auth, storage, and workflows. Framework-agnostic backend that integrates with NextJS, Remix, Hono and more.
Open Source Alternative to:
Browser and notebook combined with local-first AI
Stars
3,603Last commit
2 months agoLicense
Apache-2.0
A browser that doubles as a personal notebook, letting you research, summarize, and take notes on web pages, PDFs, and videos without switching apps.
Open Source Alternative to:
Open-source ticketing system for streamlined support
Stars
3,436Last commit
1 day agoLicense
AGPL-3.0
Frappe Helpdesk consolidates customer issues, automates workflows, and empowers self-service to boost agent productivity and customer satisfaction.
Open Source Alternative to:
Free office suite with Microsoft compatibility
Stars
Stars growing over the last 30 days4,539Last commit
10 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:
Git-native feature management for developers
Stars
4,923Last commit
4 days agoLicense
GPL-3.0
A feature flag platform that integrates with Git workflows, enabling developers to manage features directly in their codebase.
Open Source Alternative to:
Create powerful forms with ease and flexibility
Stars
Stars growing over the last 30 days3,858Last commit
3 days agoLicense
AGPL-3.0
A versatile open-source form builder for collecting data, managing submissions, and integrating with your favorite tools.
Open Source Alternative to:
Secure and elegant Matrix client for seamless conversations
Stars
3,937Last commit
22 hours agoLicense
AGPL-3.0
Cinny offers a simple, elegant, and secure interface for Matrix-based conversations, protected by end-to-end encryption.
Open Source Alternative to:
Self-hosted photo management with full control
Stars
4,311Last commit
17 hours agoLicense
MIT
Free photo management tool that runs on your server. Upload, organize, and share photos with beautiful interface, EXIF support, and complete privacy control.
Open Source Alternative to:
Automate financial processes for smarter business decisions
Stars
3,947Last commit
18 hours agoLicense
AGPL-3.0
Cloud-based accounting software that streamlines bookkeeping, generates intelligent reports, and offers multi-currency support for efficient financial management.
Open Source Alternative to:
Your digital identity, beautifully organized
Stars
3,911Last commit
16 days agoLicense
AGPL-3.0
A free, open-source link management platform for creating customizable, self-hosted link pages to showcase your online presence.
Open Source Alternative to:
AI-powered platform for engineering LLM products
Stars
Stars growing over the last 30 days3,418Last commit
19 hours agoLicense
Apache-2.0
Laminar is an open-source platform that helps collect, understand, and utilize data for building high-quality LLM applications.
Open Source Alternative to:
Create stunning data visualizations with ease
Stars
4,061Last commit
10 hours agoLicense
MIT
A powerful, open-source platform for building interactive dashboards and charts from multiple data sources without coding.
Open Source Alternative to:
Convert wearable data into actionable health insights with open algorithms
Stars
Stars growing over the last 30 days2,692Last commit
11 hours agoLicense
MIT
Self-hosted health intelligence platform with open algorithms, AI reasoning engine, and zero per-user fees. Connect Apple Health, Whoop, Garmin, Oura, and more.
Open Source Alternative to:
Effortlessly split expenses with friends and roommates
Stars
3,001Last commit
2 days agoLicense
MIT
A user-friendly app for tracking shared expenses, settling debts, and managing group finances with ease and transparency.
Open Source Alternative to:
Create your own link-in-bio page with 100+ branded buttons
Stars
3,100Last commit
3 months agoLicense
MIT
Open source DIY alternative to Linktree with 100+ branded buttons, multiple themes, and optimized performance. No frameworks or JavaScript required.
Open Source Alternative to:
Open source agency management tool for streamlined success
Stars
3,251Last commit
10 hours agoLicense
AGPL-3.0
Worklenz is a comprehensive project management platform that helps agencies organize tasks, track resources, and boost productivity.
Open Source Alternative to:
Create engaging surveys and gather valuable insights
Stars
3,770Last commit
10 hours agoLicense
Unknown
LimeSurvey is a powerful open-source tool for creating customizable online surveys, polls, and questionnaires.
Open Source Alternative to:
Complete customer relationship management made simple
Stars
Stars growing over the last 30 days3,498Last commit
1 day agoLicense
AGPL-3.0
Open-source CRM software for managing customers, companies, projects and opportunities. Intuitive interface with cloud and self-hosted options available.
Open Source Alternative to:
Lightweight code editor with agents, Git, and terminal built in
Stars
3,116Last commit
4 days agoLicense
AGPL-3.0
Open-source code editor for macOS, Windows, and Linux that puts coding agents, terminal, Git, and GitHub in a single window.
Open Source Alternative to:
Track your life, your way
Stars
3,645Last commit
2 days agoLicense
GPL-3.0
Ryot is a versatile platform for effortlessly tracking media, fitness, and more, replacing manual methods like spreadsheets.
Open Source Alternative to:
One API to deploy and run agents on any model or machine
Stars
2,946Last commit
11 hours agoLicense
Apache-2.0
Production-ready agent infrastructure that handles state, machines, permissions, and history so you don't have to build the platform yourself.
Open Source Alternative to:
Open source ecommerce platform for modern businesses
Stars
3,451Last commit
10 hours agoLicense
MIT
A flexible and customizable ecommerce solution that enables businesses to build responsive online stores with advanced features and automation capabilities.
Open Source Alternative to:
Open-source document editing suite for secure collaboration
Stars
3,381Last commit
11 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:
Craft flexible, beautiful digital experiences with ease
Stars
3,974Last commit
1 month agoLicense
Apache-2.0
A powerful, open-source CMS for Laravel that simplifies content management with a modular approach and intuitive admin panel.
Open Source Alternative to:
Professional raw photo processing made free and powerful
Stars
4,242Last commit
1 day 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:
Flexible CMS for custom digital experiences
Stars
3,617Last commit
10 hours agoLicense
Unknown
Build custom websites with a user-friendly CMS that puts content first. Features flexible architecture, GraphQL API, and powerful ecommerce capabilities.
Open Source Alternative to:
Stripe payments, usage tracking, and paywalls in 3 functions
Stars
Stars growing over the last 30 days2,829Last commit
12 hours agoLicense
Apache-2.0
Simplify Stripe integration for AI startups with 3 functions, 0 webhooks. Build pricing plans in 30 minutes with usage tracking, credits, and feature controls.
Open Source Alternative to:
Monitor, debug, and scale LLM applications with ease
Stars
Stars growing over the last 30 days2,863Last commit
11 hours agoLicense
Apache-2.0
Open-source observability platform for GenAI and LLM applications. Real-time monitoring, distributed tracing, prompt management, and AI model evaluation built on OpenTelemetry.
Open Source Alternative to:
Self-hosted social media management without limits
Stars
Stars growing over the last 30 days3,837Last commit
7 months agoLicense
MIT
Create, schedule, and manage social media content from your own server with no subscription fees or usage restrictions.
Open Source Alternative to:
Organize thousands of photos with ease
Stars
3,867Last commit
1 day agoLicense
GPL-2.0
Open source photo management software for organizing, sharing and managing large photo libraries. Perfect for teams, organizations and individuals.
Open Source Alternative to:
Transform any TV into professional digital signage
Stars
3,698Last commit
20 hours 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:
Open-source customer engagement platform for automation
Stars
3,014Last commit
8 days agoLicense
MIT
Dittofeed offers low-code tools for message automation across multiple channels, including powerful segmentation and personalization features.
Open Source Alternative to:
Track gear, bookings, and inventory without spreadsheets
Stars
3,034Last commit
10 hours agoLicense
AGPL-3.0
Open source asset management platform for teams to track equipment, manage bookings, prevent double-bookings, and handle custody and audits across locations.
Open Source Alternative to:
InfluxDB – The purpose-built time series platform for high-velocity ingestion and real-time queries at scale.
CodeRabbit
Capture
Sent