There is a W3C sponsored Community Group https://www.w3.org/community/webassembly/ https://www.w3.org/community/webassembly/. Development of the spec(s) happen

There is a W3C sponsored Community Group https://www.w3.org/community/webassembly/ https://www.w3.org/community/webassembly/. Development of the spec(s) happen in the open on the various github projects (https://github.com/WebAssembly/ https://github.com/WebAssembly/). Meeting notes, agendas, proposals, etc... are all kept as markdown in the git repositories.