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.
Open-source LLM tracing & evaluation for AI optimization
Stars
Stars growing over the last 30 days11,913Last commit
12 hours agoLicense
Elastic-2.0
Open-source platform for LLM tracing, evaluation, and optimization. Features automatic instrumentation, prompt playground, and real-time AI application monitoring.
Open Source Alternative to:
AI-powered grammar checker for 30+ languages
Stars
15,163Last commit
21 hours agoLicense
LGPL-2.1
Check grammar, punctuation, and spelling errors instantly with AI-powered technology. Supports 30+ languages with browser extensions and desktop apps.
Open Source Alternative to:
Collect, organize, cite, and share research in one place
Stars
15,674Last commit
5 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:
Simple, speedy, and secure link shortener with analytics
Stars
7,225Last commit
23 days agoLicense
AGPL-3.0
A serverless link shortener that runs entirely on Cloudflare, offering URL compression, analytics, and customizable slugs.
Open Source Alternative to:
Build product integrations with 500+ APIs in hours
Stars
Stars growing over the last 30 days12,869Last commit
8 hours agoLicense
Elastic-2.0
Complete integrations platform with 500+ pre-built APIs, code-first approach, unified data models, and enterprise-grade security. Free tier available.
Open Source Alternative to:
Beautiful open-source monitoring for modern infrastructure
Stars
10,960Last commit
22 hours agoLicense
AGPL-3.0
Monitor servers, websites, Docker containers, and infrastructure with real-time insights, instant alerts, and powerful analytics. Self-hosted solution.
Open Source Alternative to:
Voice-to-text that works offline, privately, on any app
Stars
Stars growing quickly over the last 30 days9,610Last commit
8 hours agoLicense
MIT
Dictation app powered by OpenAI Whisper and NVIDIA Parakeet. Runs locally on macOS, Windows, and Linux with zero data retention and 100+ language support.
Open Source Alternative to:
Self-hosted session replay with complete data control
Stars
13,011Last commit
7 hours agoLicense
AGPL-3.0
Open-source session replay and product analytics platform you can self-host for complete control over data security, privacy, and compliance.
Open Source Alternative to:
Secure, decentralized messaging for teams and individuals
Stars
13,600Last commit
19 hours agoLicense
AGPL-3.0
Open-source platform for encrypted communication, file sharing, and collaboration based on the Matrix protocol.
Open Source Alternative to:
Visual editing for your Git-based content
Stars
13,836Last commit
17 hours agoLicense
Apache-2.0
A headless CMS that simplifies content management with real-time editing, Git-based workflows, and developer-friendly customization.
Open Source Alternative to:
The personal finance app for everyone
Stars
Stars growing over the last 30 days10,594Last commit
1 day agoLicense
AGPL-3.0
An all-in-one personal finance platform. Track, optimize, grow, and manage your money through every stage of life.
Open Source Alternative to:
AI-Powered Note Taking App
Stars
11,104Last commit
2 months agoLicense
GPL-3.0
The next generation of open-source AI-powered card notes designed to help you quickly capture and organize inspiration so that ideas never run out.
Open Source Alternative to:
Design editor that opens Figma files, runs AI, and stays local
Stars
Stars growing over the last 30 days9,135Last commit
14 hours agoLicense
MIT
A Figma-compatible design editor with built-in AI chat, headless CLI, real-time P2P collaboration, and a Vue SDK for building custom editors. No account needed.
Open Source Alternative to:
Simple, secure project management for development teams
Stars
Stars growing over the last 30 days9,524Last commit
8 hours agoLicense
MIT
Self-hosted project management platform with visual task management, data privacy, and complete control over customization - built by developers for developers.
Open Source Alternative to:
Self-hosted Kanban board with real-time collaboration
Stars
12,626Last commit
2 days agoLicense
Unknown
Self-hosted Kanban board for agile teams. Unlimited boards, real-time sync, GDPR-compliant, and available as a free Community Edition or paid Pro.
Open Source Alternative to:
Private meeting notes, no bots, files you own
Stars
9,536Last commit
11 hours agoLicense
MIT
Records system audio without joining your call, then turns rough notes into editable summaries. Audio, transcripts, and notes stay as local files.
Open Source Alternative to:
AI-powered answer engine with dynamic interface generation
Stars
9,181Last commit
14 hours agoLicense
Apache-2.0
Open-source answer engine that dynamically generates UI components while providing AI-powered responses, combining conversational AI with interactive interfaces.
Open Source Alternative to:
Flexible spreadsheets with database power
Stars
11,978Last commit
9 hours agoLicense
Apache-2.0
A versatile data management platform combining spreadsheet simplicity with relational database capabilities for efficient data organization and analysis.
Open Source Alternative to:
Feature flags for rapid, risk-free software deployment
Stars
13,885Last commit
8 hours agoLicense
AGPL-3.0
A powerful feature management platform enabling gradual rollouts, A/B testing, and seamless integration for continuous delivery.
Open Source Alternative to:
Ultra-fast AI gateway with enterprise-grade reliability
Stars
Stars growing over the last 30 days8,957Last commit
19 hours agoLicense
Apache-2.0
Open-source AI gateway delivering 50x faster performance than alternatives. Access 1000+ models from 8+ providers with built-in governance, fallback, and observability.
Open Source Alternative to:
AI-powered PIM for managing product catalogs at scale
Stars
11,037Last commit
24 hours agoLicense
MIT
Open source Product Information Management system with an AI agent for catalog enrichment, bulk updates, multilingual content, and omnichannel distribution.
Open Source Alternative to:
Professional RAW photo editing and workflow management
Stars
13,299Last commit
15 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:
Advanced automated status page for real-time monitoring
Stars
12,354Last commit
3 days agoLicense
Apache-2.0
A highly customizable monitoring solution that provides automated status pages, extensive alerting options, and detailed testing capabilities for your services and infrastructure
Open Source Alternative to:
Realtime client-side database for collaborative apps
Stars
10,550Last commit
1 day agoLicense
Apache-2.0
Instant is a database solution for building real-time and offline-enabled applications, simplifying the development of collaborative products.
Open Source Alternative to:
Lightning-fast search for massive datasets
Stars
11,727Last commit
19 hours agoLicense
Apache-2.0
High-performance search engine designed for big data, offering scalability, real-time indexing, and cost-effective operations.
Open Source Alternative to:
Open source marketing automation for everyone
Stars
10,806Last commit
8 hours agoLicense
Unknown
Mautic is a free and open source marketing automation platform that helps businesses manage leads, create campaigns, and analyze results.
Open Source Alternative to:
Open-source integration platform for seamless workflows
Stars
14,001Last commit
8 months agoLicense
Unknown
Self-hosted automation tool that connects your apps and services, enabling powerful integrations and efficient data flow across your ecosystem.
Open Source Alternative to:
Modern payment infrastructure for digital products and SaaS
Stars
10,373Last commit
7 hours agoLicense
Apache-2.0
Comprehensive payment solution with built-in tax handling, automated benefits, and seamless integrations for digital product and SaaS businesses.
Open Source Alternative to:
Goal-driven project management for all brains
Stars
11,869Last commit
1 day agoLicense
AGPL-3.0
Open-source software designed to streamline tasks, boost productivity, and enhance collaboration for teams of all types, including those with ADHD and neurodiversity.
Open Source Alternative to:
Free online accounting for small businesses and freelancers
Stars
10,192Last commit
12 days agoLicense
Unknown
Self-hostable accounting software covering invoicing, expense tracking, cash flow, and client portals. Free to use, available in 50+ languages.
Open Source Alternative to:
Open-source document sharing with powerful analytics
Stars
9,254Last commit
2 months agoLicense
AGPL-3.0
Secure, customizable platform for sharing documents and tracking engagement. Perfect for sales teams, marketers, and businesses.
Open Source Alternative to:
Effortless time tracking for open source projects
Stars
9,020Last commit
1 day agoLicense
AGPL-3.0
Seamlessly track time across multiple projects, generate insightful reports, and optimize your open source contributions.
Open Source Alternative to:
Secure desktop investment tracker for private wealth management
Stars
9,219Last commit
13 hours agoLicense
AGPL-3.0
Wealthfolio is a simple, secure desktop app for tracking investments and managing your wealth without compromising data privacy.
Open Source Alternative to:
Send invoices, accept payments, manage your business—all free
Stars
10,302Last commit
12 hours agoLicense
Elastic-2.0
Free invoicing software for freelancers and small businesses. Create professional invoices, track expenses, accept online payments, and manage projects without hidden fees.
Open Source Alternative to:
Passwordless OIDC provider built for self-hosters
Stars
Stars growing over the last 30 days9,640Last commit
18 hours agoLicense
BSD-2-Clause
Self-hostable OpenID Connect and OAuth 2.0 provider that lets users sign in to any OIDC-compatible app using passkeys instead of passwords.
Open Source Alternative to:
Full-text & vector search at the edge.
Stars
10,581Last commit
2 days agoLicense
Unknown
Blend full-text and semantic search for unlimited queries across 300 global locations. Get precise answers and matches at a flat rate, no matter your search volume.
Open Source Alternative to:
Full-stack observability without the enterprise price tag
Stars
9,959Last commit
12 hours agoLicense
MIT
Open source observability platform unifying session replays, logs, traces, metrics and errors. Fast search, automatic clustering, $0.40/GB pricing.
Open Source Alternative to:
Visual web development with code-level control
Stars
9,093Last commit
18 hours agoLicense
AGPL-3.0
Powerful no-code platform for building responsive websites. Combines visual editing with full HTML/CSS customization.
Open Source Alternative to:
Terminal-native AI coding agent built on ZSH
Stars
7,635Last commit
17 hours agoLicense
Apache-2.0
AI coding harness that runs inside your terminal, mixes LLMs per task, and uses multi-agent architecture to handle large codebases without bloating context.
Open Source Alternative to:
Self-hosted bookmark manager built for speed and simplicity
Stars
11,319Last commit
19 days agoLicense
MIT
Minimal, fast bookmark manager with automatic metadata fetching, archiving, multi-user support, and browser extensions. Easy Docker setup with SQLite.
Open Source Alternative to:
Track, analyze, and optimize your investments effortlessly
Stars
9,533Last commit
8 hours agoLicense
AGPL-3.0
Open-source wealth management software for tracking stocks, ETFs, and cryptocurrencies across multiple portfolios
Open Source Alternative to:
Status page and uptime monitoring for growing teams
Stars
9,199Last commit
7 hours agoLicense
AGPL-3.0
Open-source status page and uptime monitor that tracks endpoints from 28 global regions, communicates incidents, and helps satisfy SOC 2 audit requirements.
Open Source Alternative to:
InfluxDB – The purpose-built time series platform for high-velocity ingestion and real-time queries at scale.
InfluxDB
Capture
Openlane