Project
Public registry for reproducible RISC-V extensions and the open .xsil packaging format.
Last updated: May 2026
ExtenSilica is a free, public registry for versioned .xsil packages — self-describing archives that bundle simulation assets, toolchains, tests, and documentation for RISC-V extension work. The open-source xsil CLI publishes, installs, and runs packages from the same catalog.
The goal is reproducible extension development with honest metadata, public adoption metrics, and a path toward neutral long-term governance of the registry format.
The platform is operated by ExtenSilica as interim technical steward. ExtenSilica is an independent project and is not affiliated with RISC-V International.
For stewardship boundaries, funding policy, and XSIL governance tokens, see Governance and Contributing.
São Paulo, Brazil
The registry and website are built and maintained from São Paulo. Community contributors and package maintainers participate from many countries; the registry itself is global and not limited to a single jurisdiction.