Best open source tools

A private-first, Toggl-compatible time tracker that can be self-hosted or used as a hosted service.

A browser-based font editor backed by a local or remote server.

Free, self-hosted group chat with rooms, direct messages, and no recurring subscription.

Organize machine-learning experiments for quantitative investment research

Self-host a software forge where repository issues are organized on Kanban boards.

A source editor for LilyPond scores with music view, MIDI playback and score-building tools.

Local personal accounts, monthly budgets and receipt attachments

A self-hosted Markdown notebook with collaboration, search, and note history.

Build a Bitcoin signer that exchanges transactions by QR code

Zcash block and transaction lookup with separate disclosure tools

Track configurable project issues and work in a self-hostable web application.

Monitor networks, servers, applications, and services with discovery, performance data collection, event processing, and alerting.

Test entry and exit rules against historical price bars

Draw together in real time on a free, open-source online whiteboard.

Runs open models locally and exposes a developer interface for using them from apps and coding tools.

Stellar wallet with a browser connection and signing interface

Open-source XMPP messaging client for business chat and group rooms.

Native Markdown notes for Mac and iPhone, stored in files you can open elsewhere.

A free project time tracker that starts without an account and can also run on infrastructure you control.

Build historical market simulations with configurable orders and costs

Stellar wallet with swap controls and a separate application-discovery view

Plan projects through text-defined work breakdowns, resource allocation, and constraint-based schedules.

An open-source iPad notebook for Apple Pencil writing and PDF markup.

A local-first Markdown knowledge base with backlinks, graphs, canvas, and Git sync.