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 AI coding agent for your editor and terminal
Stars
70,588Last commit
8 hours agoLicense
Apache-2.0
AI coding agent that runs inside VS Code and the terminal, supporting multi-file edits, bash execution, and any LLM provider via bring-your-own-key.
Open Source Alternative to:
Text-based diagramming that renders in code and docs
Stars
90,765Last commit
22 hours agoLicense
MIT
Create flowcharts, sequence diagrams, Gantt charts, and more using a simple Markdown-like syntax that renders anywhere.
Open Source Alternative to:
The leading distributed search and analytics engine
Stars
78,318Last commit
6 hours agoLicense
Unknown
Elasticsearch is an open-source, RESTful search engine designed for scalability, reliability, and easy management.
Open Source Alternative to:
AI-powered analytics workspace built for investment teams
Stars
74,465Last commit
2 days agoLicense
AGPL-3.0
Connects proprietary, licensed, and public financial data with AI agents in a self-hostable workspace for asset managers, hedge funds, and banks.
Open Source Alternative to:
Sleek, intuitive API development and testing platform
Stars
80,660Last commit
7 hours agoLicense
MIT
Lightweight, fast, and feature-rich API client for developers. Test, debug, and document APIs with ease in a clean, modern interface.
Open Source Alternative to:
Self-serve data exploration and dashboard builder
Stars
75,217Last commit
6 hours agoLicense
Apache-2.0
Connect any SQL database, build charts with drag-and-drop or raw SQL, and publish interactive dashboards without writing application code.
Open Source Alternative to:
Persistent memory layer for AI agents and apps
Stars
67,500Last commit
12 hours agoLicense
Apache-2.0
Adds persistent, searchable memory to AI agents and apps, so they remember user preferences and past interactions across sessions without pipeline changes.
Open Source Alternative to:
Docs, whiteboards, and databases in one privacy-first workspace
Stars
73,680Last commit
8 days agoLicense
MIT
An open-source, local-first knowledge base that merges structured docs, infinite whiteboards, databases, and AI into a single workspace for teams and creators.
Open Source Alternative to:
Chat with your documents using any LLM, fully private
Stars
67,343Last commit
13 hours agoLicense
MIT
A desktop and self-hostable AI app for chatting with documents, running local LLMs, and using AI agents without writing code or creating an account.
Open Source Alternative to:
LLM gateway for auth, load balancing, and spend tracking
Stars
Stars growing over the last 30 days61,627Last commit
6 hours agoLicense
Unknown
Acts as a unified proxy across 100+ LLMs, normalizing them to the OpenAI format while handling virtual keys, budgets, rate limits, fallbacks, and cost tracking.
Open Source Alternative to:
Project management for teams mixing humans and AI agents
Stars
Stars growing over the last 30 days53,267Last commit
6 hours agoLicense
Unknown
Open-source platform that manages coding agents as team members, with task queues, skill libraries, runtime monitoring, and a unified activity feed.
Open Source Alternative to:
Unified observability for metrics, logs, traces, and more
Stars
77,397Last commit
6 hours agoLicense
AGPL-3.0
Grafana unifies metrics, logs, traces, profiles, and business data into one OpenTelemetry-native platform with AI-assisted root cause analysis and adaptive cost controls.
Open Source Alternative to:
Coding agent that runs on local and open-weight models
Stars
68,614Last commit
10 days agoLicense
Apache-2.0
Coding agent that lets LLMs write and execute code, manage files, and control your computer using local or low-cost models.
Open Source Alternative to:
An independent browser engine built from scratch, not a fork
Stars
66,584Last commit
6 hours agoLicense
BSD-2-Clause
Open source web browser with its own engine, built from scratch without Blink, WebKit, or Gecko. Non-profit backed, no search deals, no user monetization.
Open Source Alternative to:
Self-hosted AI agent for chat, automation, and workflows
Stars
49,205Last commit
6 hours agoLicense
MIT
Lightweight, self-hosted AI agent that runs in a web UI, terminal, or chat app, handling long-running workflows with controlled token budgets.
Open Source Alternative to:
All-in-one business platform covering ERP, CRM, and more
Stars
55,171Last commit
6 hours agoLicense
Unknown
Integrated suite of business apps covering accounting, CRM, inventory, eCommerce, HR, and project management, available free as Community or paid Enterprise edition.
Open Source Alternative to:
Project management for teams and AI agents
Stars
61,155Last commit
1 day agoLicense
AGPL-3.0
Open source project management platform combining issues, wikis, and AI agents in one workspace. Available on cloud, self-hosted, and air-gapped deployments.
Open Source Alternative to:
Free, open-source software for video recording and live streaming
Stars
77,801Last commit
4 days agoLicense
GPL-2.0
OBS Studio offers high-quality video recording and live streaming capabilities, supporting multiple platforms and providers.
Open Source Alternative to:
Real-time monitoring for systems and applications
Stars
81,049Last commit
6 hours agoLicense
GPL-3.0
Powerful, efficient, and user-friendly monitoring solution for servers, containers, and applications with instant insights and alerts.
Open Source Alternative to:
Build a custom CRM without the proprietary lock-in
Stars
58,652Last commit
6 hours agoLicense
AGPL-3.0
Self-hostable CRM built for technical teams who need a fully customizable, extensible platform without vendor lock-in or proprietary tooling.
Open Source Alternative to:
Self-hosted timeline for quick notes, logs, and snippets
Stars
63,933Last commit
1 day agoLicense
MIT
Memos is a self-hosted, open-source note-taking app built around a private timeline. Write in Markdown, skip the folder setup, and keep your data on your own server.
Open Source Alternative to:
General-purpose AI agent for code, workflows, and more
Stars
55,457Last commit
8 hours agoLicense
Apache-2.0
Local AI agent with a desktop app, CLI, and API that connects to 15+ LLM providers and 70+ extensions for code, research, automation, and data tasks.
Open Source Alternative to:
Run open-source AI models privately on your own device
Stars
77,353Last commit
1 year agoLicense
MIT
GPT4All runs open-source language models locally on Windows, macOS, and Linux with no cloud dependency, keeping your data on your machine.
Open Source Alternative to:
Deploy apps, databases, and services to your own server
Stars
63,260Last commit
16 hours agoLicense
Apache-2.0
Self-hostable deployment platform that lets you deploy apps, databases, and 280+ one-click services to any server via SSH, with Git integration and automatic SSL.
Open Source Alternative to:
Fast GPU-accelerated terminal with native UI design
Stars
62,423Last commit
13 hours agoLicense
MIT
Experience blazing-fast terminal performance with GPU acceleration and platform-native UI. Cross-platform compatibility meets modern design.
Open Source Alternative to:
Open source metrics collection, storage, and alerting
Stars
66,665Last commit
6 hours agoLicense
Apache-2.0
Pull-based monitoring system with a multi-dimensional data model, PromQL query language, built-in alerting, and a time series database built for cloud native environments.
Open Source Alternative to:
Multi-model AI desktop client with local-first privacy
Stars
52,780Last commit
6 hours agoLicense
AGPL-3.0
Desktop AI client for Windows, macOS, and Linux that connects 300+ models from 50+ providers, with local storage, a built-in knowledge base, and autonomous agent mode.
Open Source Alternative to:
Transform databases into intuitive spreadsheets instantly
Stars
65,306Last commit
6 hours agoLicense
AGPL-3.0
Convert any database into a no-code platform with spreadsheet interface. Connect PostgreSQL/MySQL or use hosted database. Scale to millions of rows effortlessly.
Open Source Alternative to:
Self-host your own scheduling page, no vendor required
Stars
49,167Last commit
19 hours agoLicense
MIT
Cal.diy is the community edition of Cal.com for personal self-hosting, with calendar sync, video conferencing, payment support, and a REST API.
Open Source Alternative to:
One interface for all your AI models and conversations
Stars
Stars growing over the last 30 days46,041Last commit
6 hours agoLicense
MIT
Chat with multiple AI providers through a single self-hostable interface, with support for custom agents, file uploads, plugins, and multi-user access control.
Open Source Alternative to:
Self-hosted media server for movies, music, and more
Stars
58,277Last commit
1 day agoLicense
GPL-2.0
Free, open source media server that lets you collect, manage, and stream your personal library to any device, with no fees, tracking, or vendor lock-in.
Open Source Alternative to:
Self-hosted Git service for seamless collaboration
Stars
58,582Last commit
10 hours agoLicense
MIT
A lightweight, fast, and customizable Git service that simplifies code hosting and collaboration for teams of all sizes.
Open Source Alternative to:
Self-hosted AI runtime for text, voice, vision, and agents
Stars
49,758Last commit
6 hours agoLicense
MIT
Run LLMs, speech, image generation, and autonomous agents on your own hardware with an OpenAI-compatible API and 60+ swappable backends.
Open Source Alternative to:
Open-source UI design and prototyping for product teams
Stars
61,407Last commit
6 hours agoLicense
MPL-2.0
Design, prototype, and hand off to developers in one platform. Supports design systems, tokens, flexible layouts, and AI workflows with real CSS/HTML output.
Open Source Alternative to:
Publishing platform for blogs, newsletters, and paid memberships
Stars
55,575Last commit
7 hours agoLicense
MIT
Publish content, send email newsletters, and sell paid subscriptions from one platform. Used by independent journalists, creators, and businesses like YCombinator and Kickstarter.
Open Source Alternative to:
A full desktop environment that runs in your browser
Stars
43,822Last commit
6 hours agoLicense
AGPL-3.0
Puter is a cloud-based desktop OS you run in the browser, with built-in apps, file storage, and support for hosting web apps and sites.
Open Source Alternative to:
Encrypted note-taking that syncs across all your devices
Stars
56,810Last commit
1 day agoLicense
Unknown
Cross-platform note-taking app with end-to-end encryption, Markdown support, web clipping, and sync via Dropbox, OneDrive, or Joplin Cloud.
Open Source Alternative to:
Open source payment orchestrator for global transactions
Stars
Stars growing over the last 30 days45,378Last commit
7 hours agoLicense
Apache-2.0
A unified payment infrastructure that connects multiple payment processors through a single API integration, enabling global payment processing
Open Source Alternative to:
Lightweight, fast, and open-source API client for developers
Stars
47,756Last commit
1 day agoLicense
MIT
A modern, user-friendly API client that simplifies API testing and development with a clean interface and powerful features.
Open Source Alternative to:
AI-powered research notebook with full privacy control
Stars
40,402Last commit
2 days agoLicense
MIT
Combines AI summarization, podcast generation, and multi-format content ingestion for researchers and students who want to keep their data private.
Open Source Alternative to:
Team chat, project management, and AI agents in one place
Stars
Stars growing over the last 30 days36,168Last commit
11 hours agoLicense
Apache-2.0
Workspace that combines team chat, project planning, and git management with AI agents that collaborate alongside your team on shared context.
Open Source Alternative to:
Free instant whiteboard with real-time collaboration
Stars
51,001Last commit
17 hours agoLicense
Unknown
Virtual whiteboard that works instantly on any device, no signup required, with real-time multiplayer collaboration built in.
Open Source Alternative to:
c15t – Open-source cookie banner, built for control and lightening fast modern web apps.
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InfluxDB
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