Open Source Projects using Kotlin
A curated collection of the 61 best open source software using Kotlin. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.
Team chat with email, tasks, and docs in one workspace
Stars
3,991Last commit
10 hours agoLicense
AGPL-3.0
Team chat app with inline threads, mention-based sharing, a unified inbox for chat and email, and an AI agent that works across your full workspace.
Open Source Alternative to:
Task management with GitHub sync and AI agents for devs
Stars
3,991Last commit
10 hours agoLicense
AGPL-3.0
Task manager built for engineering teams, combining status tracking, priority management, GitHub integration, and AI agents that can close tasks automatically.
Open Source Alternative to:
Markdown docs wired into tasks, email, and agents
Stars
3,991Last commit
10 hours agoLicense
AGPL-3.0
Collaborative markdown documents with real-time CRDT editing, AI agent cursors, mention linking, and built-in properties tied to your tasks, channels, and email.
Open Source Alternative to:
A self-building CRM powered by your email
Stars
3,991Last commit
10 hours agoLicense
AGPL-3.0
Automatically creates and enriches contacts, companies, and deal threads from your team's email. No data entry, no imports, no admin overhead.
Open Source Alternative to:
Keyboard-first email client with AI, chat, and tasks
Stars
3,991Last commit
10 hours agoLicense
AGPL-3.0
An AI-powered email client that combines inbox management, chat, tasks, and AI agents in one shared workspace, built for keyboard-driven workflows.
Open Source Alternative to:
Open-source localization platform for multilingual apps
Stars
4,080Last commit
12 hours agoLicense
Apache-2.0
Manage app translations with in-context editing, AI translation, and collaborative tools. Self-hostable and free to start.
Open Source Alternative to:
An AI assistant that acts, not just answers
Stars
387,237Last commit
9 hours agoLicense
MIT
A personal AI assistant that connects to your existing chat apps and handles real tasks like email, calendar, and flight check-ins on your behalf.
Open Source Alternative to:
Run LLMs locally with minimal setup, maximum hardware support
Stars
125,296Last commit
9 hours agoLicense
MIT
C/C++ inference engine for large language models, supporting quantization, multi-GPU, Apple Silicon, and an OpenAI-compatible server across a wide range of hardware.
Open Source Alternative to:
Self-hosted remote desktop you fully control
Stars
121,576Last commit
2 days agoLicense
AGPL-3.0
Cross-platform remote desktop software that runs on your own servers, giving you full data control as a direct alternative to TeamViewer and AnyDesk.
Open Source Alternative to:
Self-hosted photo and video backup for your own server
Stars
112,435Last commit
9 hours agoLicense
AGPL-3.0
Back up, organize, search, and browse your personal photo and video library on your own server, with no third-party cloud access.
Open Source Alternative to:
Free 2D and 3D game engine for cross-platform projects
Stars
116,040Last commit
2 days agoLicense
MIT
Build 2D, 3D, and XR games with a full-featured engine that includes its own scripting language, scene editor, and export tools for multiple platforms.
Open Source Alternative to:
Postgres-powered backend platform for production apps
Stars
108,319Last commit
18 hours agoLicense
Apache-2.0
Provides a full backend stack built on Postgres: authentication, auto-generated APIs, edge functions, realtime subscriptions, file storage, and vector search.
Open Source Alternative to:
Share files securely across all devices without servers
Stars
89,111Last commit
3 days agoLicense
Apache-2.0
Free, open-source file sharing tool for nearby devices. Cross-platform support with end-to-end encryption, no registration required, automatic device discovery.
Open Source Alternative to:
AI workspace for docs, projects, and wikis you control
Stars
75,883Last commit
13 days agoLicense
AGPL-3.0
Open source collaborative workspace combining notes, databases, and AI with full data ownership, offline support, and self-hosting options.
Open Source Alternative to:
Docs, whiteboards, and databases in one privacy-first workspace
Stars
71,798Last commit
17 hours 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:
An independent browser engine built from scratch, not a fork
Stars
65,805Last commit
11 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:
Run multiple AI coding agents in parallel, side by side
Stars
51,692Last commit
9 hours agoLicense
MIT
Agent Development Environment that runs Claude Code, Codex, Gemini, and other CLI agents in parallel across isolated git worktrees, with terminals, browser, diff review, and git tools built in.
Open Source Alternative to:
Encrypted note-taking that syncs across all your devices
Stars
56,065Last commit
9 hours 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:
Privacy-first knowledge base that connects your notes
Stars
44,574Last commit
10 hours agoLicense
AGPL-3.0
Local-first, open-source knowledge management tool with bidirectional linking, outlines, flashcards, PDF annotations, and whiteboards for building a connected second brain.
Open Source Alternative to:
Team chat, project management, and AI agents in one place
Stars
29,995Last commit
10 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:
Open-source coding agent for your IDE and terminal
Stars
35,603Last commit
1 day agoLicense
Apache-2.0
Runs source-controlled AI checks on every pull request, enforcing your engineering standards as native GitHub status checks with suggested fixes.
Open Source Alternative to:
Your personal distributed filesystem
Stars
38,836Last commit
26 days agoLicense
AGPL-3.0
A cross-platform file manager that unifies your devices into a seamless, organized digital workspace.
Open Source Alternative to:
AI-powered code completion for seamless development
Stars
33,831Last commit
2 months agoLicense
Apache-2.0
Self-hosted AI coding assistant that enhances productivity with context-aware suggestions and privacy-focused implementation.
Open Source Alternative to:
Secure, private photo storage and sharing solution
Stars
28,469Last commit
16 hours agoLicense
AGPL-3.0
End-to-end encrypted cloud storage for photos and videos, offering privacy, security, and seamless cross-device syncing.
Open Source Alternative to:
Private messaging with end-to-end encryption
Stars
29,244Last commit
2 days agoLicense
AGPL-3.0
Secure messaging app with state-of-the-art encryption, voice/video calls, group chats, and file sharing. No ads, trackers, or data collection.
Open Source Alternative to:
Open-source data integration for modern teams
Stars
21,941Last commit
1 day agoLicense
Elastic-2.0
Seamlessly sync data from any source to any destination with a flexible, extensible platform that grows with your data needs.
Open Source Alternative to:
Social media reimagined for community and connection
Stars
18,231Last commit
2 days agoLicense
MIT
A decentralized social network focused on fostering meaningful interactions and giving users control over their data and experience.
Open Source Alternative to:
Run coding agents from your phone, desktop, or terminal
Stars
14,776Last commit
9 hours agoLicense
AGPL-3.0
Self-hosted orchestrator for coding agents like Claude Code, Codex, and Cursor, controlled from phone, desktop, web, or CLI.
Open Source Alternative to:
Task manager built for deep work, privacy, and focus
Stars
21,532Last commit
9 hours 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
19,564Last commit
3 days agoLicense
AGPL-3.0
Open-source platform to collect, organize, and preserve webpages with powerful collaboration features
Open Source Alternative to:
Privacy-first survey and experience management platform
Stars
12,806Last commit
18 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:
Zero-knowledge encrypted notes that sync across all devices
Stars
14,455Last commit
3 days agoLicense
GPL-3.0
End-to-end encrypted note-taking app with zero-knowledge architecture, cross-device sync, web clipper, and a self-hostable sync server.
Open Source Alternative to:
Build full-stack apps with TypeScript and real-time sync
Stars
12,416Last commit
2 days agoLicense
Unknown
Open-source reactive database that keeps your web and mobile apps in sync. Write everything in TypeScript with built-in auth, cron jobs, and AI integration.
Open Source Alternative to:
Free, open-source framework for cross-platform game development
Stars
14,334Last commit
3 days agoLicense
Unknown
Build games in C# that run on Windows, macOS, Linux, iOS, Android, and major consoles. No royalties, no subscriptions, no runtime fees.
Open Source Alternative to:
Common layer for composing and governing AI agents
Stars
9,193Last commit
17 hours agoLicense
Apache-2.0
Meta-harness that sits above Claude Code, Codex, and other AI agents to add policy enforcement, sandboxing, and real-time collaborative sessions.
Open Source Alternative to:
AI-Powered Note Taking App
Stars
10,939Last commit
21 days 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:
Self-hosted session replay with complete data control
Stars
12,557Last commit
3 days 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:
The personal finance app for everyone
Stars
9,583Last commit
9 hours 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:
Serverless backend platform for modern app development
Stars
9,280Last commit
12 hours agoLicense
MIT
Fully managed backend infrastructure with built-in authentication, database, storage, and serverless functions for rapid application development.
Open Source Alternative to:
Visual development platform for modern web experiences
Stars
8,806Last commit
2 days agoLicense
MIT
Drag-and-drop interface for creating and optimizing digital experiences, with headless CMS and powerful integrations.
Open Source Alternative to:
Fast, flexible VPN replacement with zero-trust security
Stars
9,039Last commit
12 hours agoLicense
Apache-2.0
Replace your VPN with zero-trust access built on WireGuard. Fast, scalable network security with simple policies and identity provider integration.
Open Source Alternative to:
Simplify expense management for businesses of all sizes
Stars
5,011Last commit
9 hours agoLicense
MIT
Automate expense reporting, reimbursements, and corporate card management with real-time data sync and powerful integrations.
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