Top Open Source Projects using CSS

A curated collection of the 521 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.

Workadventure

A customizable virtual world where teammates move as avatars and video chat starts the moment they walk up to each other.

Alternative to:

Gather

Virtual office platform for engaging remote collaboration

Stars
5,747
Forks
943
Last commit
6 days ago

BleachBit

A desktop cleaner that deletes junk files to free disk space and remove traces that would otherwise linger on a machine.

Alternative to:

CCleaner

Clean your system and free disk space

Stars
6,819

Permify

A fine-grained authorization service modeled on Google Zanzibar, for teams that want permission logic out of application code.

Alternative to:

Oso

Build scalable authorization in minutes, not months

Stars
5,949

Standard Notes

An end-to-end encrypted notes app that syncs across desktop, mobile and web for people who want their notes unreadable to the host.

Alternative to:

Notion

Secure, encrypted notes for your digital life

Stars
6,622

5ire

A desktop AI assistant and MCP client that talks to major model providers and indexes your own documents locally.

Alternative to:

ChatGPT

Smart desktop AI assistant with powerful local knowledge features

Stars
5,344

Passbolt

A password manager for teams built on user-owned keys and end-to-end encryption, for organizations sharing credentials without trusting a vendor.

Alternative to:

1Password

Secure password management for teams

Stars
6,111

ACI.dev

A tool-calling platform that connects AI agents to hundreds of services with managed authentication, permissions and dynamic tool discovery.

Alternative to:

Composio

Build reliable AI agents with unified tool integration

Stars
4,889

Kener

A lightweight status page system with monitors, incidents and maintenance windows, for teams that want a branded page quickly.

Alternative to:

UptimeRobot

Deploy a professional status page in minutes, no coding required

Stars
5,148

Inngest

A durable execution platform replacing queues, state management and scheduling so developers write reliable background jobs and workflows as code.

Alternative to:

AWS Step Functions

Effortless event-driven workflows for modern applications

Stars

Digger

Terraform and OpenTofu automation that runs plan and apply inside your existing CI, driven from pull request comments.

Alternative to:

HCP Terraform

Terraform automation with pull request workflows

Stars
5,040

Agenta

Open-source workspace where teams build agents by chatting with them, connect them to apps, and run them in the background.

Alternative to:

Lindy

Build, automate, and improve AI agents with your team

Stars
4,709

Colanode

Local-first collaboration workspace you self-host, combining chat, wiki pages, databases, and file storage for teams that want to own their data.

Alternative to:

Notion

Self-hosted team workspace with chat, docs, and databases

Stars
5,097

Kimai

Time tracking application for freelancers and companies, with invoicing, budgets, exports and reporting across multiple users, timezones and languages.

Alternative to:

Toggl Track

Effortless time tracking for teams and projects

Stars
4,959

Vikunja

Self-hosted task manager with a documented API, desktop client and hosted option, aimed at people who would rather own their to-do list.

Alternative to:

Asana

Organize, collaborate, and conquer your tasks

Stars
5,304

useSend

Open-source email sending platform built on Amazon SES, covering transactional mail, marketing campaigns, contacts and delivery analytics from a single dashboard.

Alternative to:

Mailgun

Pay per email sent, not for contact storage

Stars
4,659

Proton Lumo

Proton's confidential AI chat assistant, storing every conversation with zero-access encryption so that not even Proton can read your chat history.

Alternative to:

ChatGPT

Private AI chat with zero-access encryption

Stars
5,575

Mathesar

Spreadsheet-like web interface for PostgreSQL that lets users of any skill level view, edit, query and collaborate on data directly.

Alternative to:

Airtable

Spreadsheet-like interface for PostgreSQL databases

Stars
5,114

Frappe Books

Desktop accounting application for small and medium businesses, with double-entry bookkeeping, invoicing, point of sale and financial reports, working fully offline.

Alternative to:

FreshBooks

Modern desktop accounting made simple and free

Stars

Latitude

Observability platform for AI agents that traces every run, groups failures into tracked signals, and dispatches coding agents to fix them.

Alternative to:

LangSmith

Full observability for AI agents in production

Stars
4,632

/dev/push

Self-hosted deployment platform that builds and runs any Docker-compatible app from a git push, with zero-downtime rollouts and instant rollback.

Alternative to:

Vercel

Deploy apps instantly with git push - open source alternative

Stars
4,745

Statamic

Flat-first CMS for Laravel applications, storing content in files that live in Git rather than rows in a database.

Alternative to:

Contentful

Craft flexible, powerful websites with ease

Stars
4,885

Hi.Events

Self-hosted ticketing and event management platform for conferences, festivals and club nights, keeping branding, checkout and attendee data on your infrastructure.

Alternative to:

Cvent

Effortlessly manage events and sell tickets online

Stars

Frappe CRM

Open-source CRM for sales teams with unlimited users, offering kanban pipelines, a consolidated deal page and built-in telephony and WhatsApp integrations.

Alternative to:

HubSpot

Open-source CRM that puts simplicity and control first

Stars

Drupal

Content management platform for sites of any size, from a personal weblog to a large community-driven site, extended by thousands of free modules.

Alternative to:

Contentful

Build powerful websites with the open-source CMS

Stars
4,281

Shopware

Headless ecommerce platform on Symfony and Vue.js that works as a ready-made shop system or as a framework for custom commerce.

Alternative to:

Shopify

Open source ecommerce platform for modern businesses

Stars
3,419

Pipeshub

Open-source workplace AI platform that connects company knowledge across business systems and answers questions with citations, respecting each person's permissions.

Alternative to:

Coveo

Enterprise workplace AI with data you own and control

Stars

Jitsu

MIT-licensed event data platform that collects behavioral events and delivers them to warehouses and SaaS tools, a self-hostable Segment alternative.

Alternative to:

Fivetran

Open-source data integration for modern stacks

Stars
5,063

Erxes

Source-available experience operating system that unifies marketing, sales, operations and support in one self-hosted, plugin-based platform for growing businesses.

Alternative to:

HubSpot

Open-source growth platform for customer-centric teams

Stars
4,074

Ever Gauzy

Open business management platform bundling ERP, CRM, HRM, applicant tracking, project management and time tracking for agencies, studios and on-demand teams.

Alternative to:

Microsoft Dynamics 365

Comprehensive open-source business management platform

Stars

Rallly

Self-hostable group scheduling tool where participants vote on proposed dates, replacing the email back-and-forth of finding a meeting time.

Alternative to:

Doodle

Effortless group scheduling for seamless collaboration

Stars
5,248

Deta Surf

Local-first AI notebook and browser that keeps files, web pages and notes in one place so research and writing happen side by side.

Alternative to:

NotebookLM

Browser and notebook combined with local-first AI

IronCalc

Spreadsheet engine written in Rust that reads and writes xlsx files and is designed to be embedded across several programming languages.

Alternative to:

Google Sheets

A spreadsheet engine you can embed, self-host, or run in the browser

Stars

Tracecat

Open source security automation platform combining agents, workflows, lookup tables and case management for security teams that prefer writing Python.

Alternative to:

Cortex XSOAR

Open source security automation platform for builders

Stars

Flipt

Git-native feature flag platform that stores flags in your own repositories, so flag changes ship through the same review path as code.

Alternative to:

LaunchDarkly

Git-native feature management for developers

Stars
4,888

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Top Open Source Projects using CSS

A curated collection of the 521 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.

Workadventure

BleachBit

Permify

Standard Notes

5ire

Passbolt

ACI.dev

Kener

Inngest

Digger

Agenta

Colanode

Kimai

Vikunja

useSend

Proton Lumo

Mathesar

Frappe Books

Latitude

/dev/push

Statamic

Hi.Events

Frappe CRM

Drupal

Shopware

Pipeshub

Jitsu

Erxes

Ever Gauzy

Rallly

Deta Surf

IronCalc

Tracecat

Flipt

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