What it does
The Satoshi Nakamoto Institute is an archive. Its about page states that it "was founded in November 2013 to advance and preserve knowledge of Bitcoin's history, economics, and technology", and that it "is a Texas nonprofit corporation exempt from tax under Section 501(c)(3) and classified as a public charity". Its footer dates its founding by block height rather than by calendar: "Established block #272,311".
Its central holding is The Complete Satoshi, which gathers everything the author of the whitepaper published under that name between 2008 and 2012, sorted into the whitepaper, emails, forum posts, code and quotations. The value of it is boring and considerable: a stable, dated, linkable copy of primary text that would otherwise be scattered across a dead mailing list archive, a forum and a defunct SourceForge page. The site treats the name as what it is, a pseudonym, and makes no claim about who used it.
Around that sits the Library, which holds the work Bitcoin was built out of: Nick Szabo on bit gold, Hal Finney, David Chaum on digital cash, the cypherpunk essays, and the Austrian economics that a good deal of Bitcoin's early writing argues from. The collection's own framing is that "Bitcoin was not forged in a vacuum. These works serve to contextualize bitcoin into the broader story of cryptography and freedom." Everything is free to read, and the site is published under a Creative Commons Attribution-ShareAlike 4.0 licence.
What is on the record about it
The Internal Revenue Service records reproduced by ProPublica list the Satoshi Nakamoto Institute of Austin, Texas, employer identification number 38-4296073, as a 501(c)(3) charitable organisation with a ruling date of February 2024, reporting revenue of $137,537 against expenses of $107,445 for that year. So the archive ran for a decade before the tax exemption arrived, on the volunteer basis the site still asks for: it solicits donations, developers and translators, and takes translations as pull requests on GitHub.
No officers or contributors are named anywhere on the site, so none are listed here.