Ruby gems — one organisation each

A Ruby virtual machine is only useful with a library around it, so each gem the ecosystem needs is reimplemented in pure Go in its own go-ruby-* organisation: the standard library, Rails and its dependencies, the testing stack, the Puppet stack, database drivers, serialisation formats and template engines.

Every one of them is byte-compared against MRI where a byte comparison is meaningful — a checksum, a Marshal payload, a formatted number. Where it is not (a deflate stream, say, whose output is implementation-defined) the requirement is interoperability in both directions instead.

Two things to know before reaching for one:

• The gem organisation is the Ruby-facing wrapper, not always the engine. Some are thin shells over an engine that lives in its own non-Ruby organisation — the regexp gem wraps go-regexp/engine, the sass gem wraps go-scss/scss. If you are writing Go rather than Ruby, take the engine.
• The repository inside is named after the gem, not after the organisation: go-ruby-activerecord/activerecord.

195 gem organisations, 195 public code repositories.