How this site is made.

What gets on the list

An entry needs three things: a public repository or dataset, a clear use in tax work, and an open licence or a clear warning where we could not confirm one. It also needs a working link, and it has to be about tax. The list holds 733 entries today.

What stays out: projects that are not about tax, forks and duplicates, dead links, and commercial products. Tools for individual taxpayers (107 today) are listed with the label "For individual taxpayers" and stay off the map, which shows a company's tax department and a tax authority. A tool built by or for a tax authority counts as an authority project, even when it serves citizens.

A vendor's open code goes on the list like anyone else's. Where it needs the vendor's paid service, the label says so. Coverage is compared with a generic status quo, never with a named vendor.

How entries are reviewed

Every candidate goes through a review sheet with a decision and a reason per row. The description is one sentence written from the project's own page. 549 entries carry a longer note: two or three sentences from the README on what the tool does, what it needs and what to check, written on the day the facts were checked, never from memory.

We have not reviewed entries for quality or tax accuracy. The honest reads on the map and the briefs on the gaps page are drafts until a tax specialist has reviewed them, and each one says so.

What the labels mean

• Maintained, inactive, archived. Maintained means a commit in the twelve months before the check date; inactive means none; archived means the repository is archived, or its README says the project is discontinued. 556 entries are maintained today.
• Demo. The code shows an idea and computes nothing you should rely on.
• Needs a paid service. Open code that only works with a paid service behind it.
• Licence warnings. Three kinds: 215 entries have no licence we could recognise, 6 allow only non-commercial use, and 6 are source-available with limits on reuse. Check with the maintainers before you reuse them.
• For individual taxpayers. Personal returns, capital gains, crypto, and tools for freelancers, sole traders and owner-managed businesses.

How the map is decided

The map draws two organisations, 19 teams and 35 activities. Each activity has one state: covered (6), partly covered (23), gap (3) or people only (3). The state follows the projects placed on the activity: an activity is never marked covered without at least one real project behind it, and a gap is an activity with none.

A project earns a place on the map when it is maintained, serves a company tax department or a tax authority, and carries no demo or paid-service flag. 366 of 733 entries sit on the map today; the rest stay on the list with their labels. The scorecard, the team counts and the gaps page are all computed from the same activity lists. Nothing is counted by hand.

"Start with" lines name one or two projects per activity, chosen for maintenance, licence and fit, with one sentence why. They are a place to begin, not a ranking. Each gap carries a brief: what to build on, what a first version could do, and which Learn track helps.

Keeping it true

The facts behind every entry (the last commit, the archive flag, the stars) were checked on 6 Oct 2026. Once a month, a script re-reads every GitHub entry and proposes the changes; a person reviews them before they reach the site. A state on the map changes only by hand.

What changed lists the additions and the changes to the map by month, with a feed you can follow.

What we do not do

• No ranking. Lists are ordered by name, with entries that carry a warning after the others.
• No invented numbers. Every count on the site is computed from the data files when the site is built.
• No comparison with a named vendor, and no vendor logos.
• No lesson written by a machine. Lessons on Learn are written by people, or stay outlines.
• No tax advice. Statements about rules, rates and deadlines are flagged for specialist review before they ship.

Correct an entry, or add one

Found a mistake, a dead link or a missing project? Email pascal@lurn.digital with the link. Every project's page has a "Suggest an edit" link that opens the same address with the entry's name.

The data is yours to reuse: CSV and JSON, under CC BY 4.0, with where each project fits, who it is for, its status and its notes.

Who runs it

tax-oss.com is run by Frontr.tax. It is a community project, not affiliated with any tax technology vendor, and its content is CC BY 4.0. The manifesto holds the promises the site holds itself to; the privacy notice says what the site collects.