Implementation Rules by Entry Type
Every entry declares a type in meta.json - what it is and how it is ranked. The split is about what the entry is, not how featureful it is: a server applications are written against is a framework entry however thin, and the framework tiers then grade how production-proven it is. Framework entries (Flagship / Emerging / Experimental) additionally declare a mode (Standard or Tuned).
FrameworksServers you write application code against, tiered by how production-proven they are. Run in Standard or Tuned mode.EngineHTTP implementations applications are not written against (raw sockets, custom parsers, WSGI/ASGI hosts). Ranked separately.InfrastructureReverse proxies and static-file servers (nginx, Caddy, h2o) without an app framework layer.