Useful open-source software, by category
GitHub hosts an enormous number of repositories, and most of them are personal experiments or abandoned. This directory lists only maintained projects that solve a real job for a person or a small business, grouped by category. For each one we read the repository, the licence file and the pricing page, so you can see what it does, who it suits, what it really costs and how to install it.
Quick answer
Each category page compares several open-source projects for one job, such as PDF tools or invoicing. Every entry gives a plain description, how it is used, the licence, whether it is fully free, open-core or sold as a hosted plan, setup steps taken from the official docs, and the project's GitHub stars and last update on the date we checked.
- PDF and document toolsEight open-source PDF projects compared: Stirling PDF, BentoPDF, PDFsam, OCRmyPDF, Paperless-ngx, PDF.js, qpdf and PyMuPDF. What each does, licence, free or paid, and setup steps from the official docs.8 projects · Checked 18 October 2026Compare
- Invoicing and accountingNine open-source invoicing, accounting and budgeting apps compared: Invoice Ninja, InvoiceShelf, Akaunting, Bigcapital, Kimai, Firefly III, Actual Budget, GnuCash and Beancount, with licences, real costs and setup steps.9 projects · Checked 18 October 2026Compare
- ERP and CRM for small businessNine open-source ERP and CRM systems for small businesses compared: ERPNext, Odoo Community, Dolibarr, Axelor, Tryton, Twenty, EspoCRM, Krayin and Frappe CRM, with licences, what is free, hosted prices and setup steps.9 projects · Checked 19 October 2026Compare
Categories coming next
Office suites and document editors · Password managers and 2FA · Photo and image editing · Website builders and CMS · Online stores · Self-hosted cloud storage · Notes and knowledge bases · Project management and team chat · Privacy-friendly web analytics · Automation and workflows · Local AI tools
How a project gets on this list
It must have had code pushed in the last twelve months, a clear licence, official installation docs and an obvious use for everyday people or small businesses. Popularity alone is not enough: we leave out well-known projects that have gone quiet, and we say so on the page.
Where the numbers come from
Stars, licence and last-push dates come from GitHub's public data (read through repos.ecosyste.ms, which mirrors the GitHub API) on the date shown. Licences are confirmed in each project's LICENSE file and prices on the project's own pricing page. Stars and prices change, so treat them as a snapshot.
Free, open-core or paid hosting
"Free" means the project sells nothing for it. "Open-core" means the core is free but some features or licences are paid. "Free + paid hosting" means you can run it yourself for free, or pay the project to host it. Some popular apps are source-available rather than open source; we name the licence so you can decide.
Questions about this directory
Why not list every repository on GitHub?
Because most of them are not useful to install: tests, personal projects, forks and abandoned code. A short, checked list per category saves you from trying tools that no longer work.
Are open-source tools always free?
Free to download, yes, but not always free to use however you like. Some licences limit users or forbid offering the software as a service, and running your own server has costs. Each entry says which applies.
Do you get paid to list these projects?
No. Nothing here is sponsored and there are no affiliate links. Projects are chosen by the rules on this page.
How often is the directory updated?
We add new categories regularly and re-check every published category each month: stars, last update, licence, prices and setup steps.
Is open-source software safe to install?
Install only from the official repository or website linked here, prefer official releases or images over random downloads, and keep the software updated. Self-hosted apps that hold money or documents also need backups and a secure server.