The projects that joined the list and the changes to the map, newest first. Entries have carried the month they joined since October 2026; earlier entries carry none. How the list is made is on the method page.
Oct 2026
298 entries joined the list, as of 6 Oct 2026. See the list, sorted by newest.
Three entries left the list: their repositories are gone
ANTON's transfer pricing modules, the US Sales Tax Rates Dataset and CustomsIQ were removed because their repositories are no longer public. Transfer pricing stays partly covered and indirect tax stays covered. Four links to folders or repositories that had moved now point to their new places, and one repository archived by its maintainer carries the label.
Every project and every activity has its own page
Each of the 736 entries now has a page with its facts, notes, place on the map and the Learn pages that name it, and each of the 35 activities has one with its read, its projects and its brief. The list can be browsed by tax area, jurisdiction and kind.
The four steps start with the map
The story now runs Map, Projects, Gaps, Learn: where tax work happens and by whom, what is open for it, what is missing, how to build it. The gaps page lists the partly covered activities too, with what is still missing.
Research packages and datasets join the list
55 replication packages, research datasets and data portals are listed as tax datasets, 10 of them on the map, each with its record's latest version as its last update. Packages written for confidential data stay out.
The tax authority has no gap left
A third sweep found 110 projects. Returns processing, payments and debt collection, and clearance platforms are now partly covered on the authority side; tax accounting, international tax, M&A and tax risk management on the company side. Three company gaps remain: forecasting, planning and controls.
Customs and trade tax is partly covered
A second sweep over Pillar Two, country-by-country reporting, exchange of information and customs found 218 candidates; 135 joined the list, 72 of them on the map. An authority's several repositories for one service are listed as one entry.
Exchange of information is partly covered
A first sweep over Pillar Two, country-by-country reporting and exchange of information added 18 projects, five of them on the map, and the exchange of information activity gained its first open tool.
Transfer pricing, Pillar Two and transparency reporting are partly covered
65 transfer pricing tools, skills and plugins joined the list, 31 of them on the map. Transfer pricing, Pillar Two and transparency and external reporting moved from gap to partly covered, each with a read that says what is still missing.
Notes on what each tool does, needs and should be checked for
Entries carry two or three sentences read from their README on the day the facts were checked: what the tool does, what it needs, what to check. They show in the expanded row on the list, on each project's page and in the downloads.
The map says where to begin
Every covered and partly covered activity shows its honest read and a start-with line: one or two projects and one sentence why, chosen for maintenance, licence and fit.
Six more glossary terms and five how-to guides on Learn
The glossary adds the tax-technical terms a reader meets in open tooling, each with examples from the list. Five how-to guides name only listed tools: checking a VAT number from an agent, reading official guidance as data, filing a UK corporation tax return from the command line, drafting a Master File, running a policy simulation.
Three kinds of licence warning
Entries without a licence we could recognise, entries that allow only non-commercial use, and source-available entries with limits on reuse each carry a badge and a note. The counts on the list come from the data.
The facts are refreshed monthly
A script re-reads every GitHub entry's last commit, archive flag and stars once a month and proposes the changes; a person reviews them before they reach the site. The first run is due on 1 November 2026.
Every open source tax project with a working link is listed
The list opened to every open source tax project: personal-tax tools, inactive and archived repositories, demos and clients for a paid service are listed with a label that says what to check. Only maintained projects for companies and tax authorities sit on the map.