It comes with a local disk-based service for development and testing and supports mirroring files to subordinate services for backups and migrations.

@Rei_mk2 文档开头这句话的意思，local disk-based service 只是为了 development 和 test 用的吧。

I long dreamed of using Objective C to build server apps. The compiler support has been there for years (GCC, later Clang), but there's no standard library. All the stuff you would want from Foundation is missing; strings, sockets, file I/O, encoding support, threads, etc., it turns out you'd have to reimplement a lot from scratch. There's GNUstep, but last I looked it, it was stagnant, and also very much geared towards GUI apps. Swift on the backend would be even better, I think. Between all the languages that have evolved lately (including Go and Rust), Swift has struck me as the one that feels the most like my ideal language.

我与 HN 上这位兄台的观点一致