Some excerpts from the site, for the lazy:
Catallax is intended to facilitate uncensorable, decentralized labor markets and permissionless payments.[Escrow] advertisements, Task postings and their eventual resolutions are posted on the Nostr protocol while payments are handled via Cashu ecash and Lightning. Thanks to Cashu-based wallets and Nostr’s permissionless identity creation, anyone (namedoxxed or nym) can participate in the Catallax economy without conforming to KYC or AML nor first having a Bitcion or Lightning wallet configured.All you need is a web browser.Rather than involving blockchains, smart contracts or complicated oracles and voting systems, the Catallax protocol relies on lindy technology: trust and reputation.
Here is the Nostr NIP draft PR
I'm working on the initial reference implementation client and relay. When those are done and minimally testable (a couple weeks, probably), you'll see another SN post!