Why pure Go

The go-ruby-stdlib family reimplements the Ruby standard library in pure Go, with cgo disabled. The slice of Ruby each module covers is deterministic and interpreter-independent: given its inputs, the result is a pure function of those inputs — no live binding, no evaluation of arbitrary Ruby. That is exactly the part that can — and should — live as a standalone Go library, separate from the interpreter.

Extracted from rbgo, reusable by anyone

These libraries began life inside go-embedded-ruby's rbgo — in the prelude/internals that back the Ruby surface. They have been extracted into reusable standalone libraries so that:

• any Go program can import a module directly (e.g. github.com/go-ruby-set/set), with no Ruby runtime;
• the dependency runs the other way — rbgo binds each module as a native module, rather than the module depending on the interpreter;
• behaviour is pinned by a differential oracle against the system ruby, independent of any one consumer.

Why pure Go matters here

Because every module is CGO-free, it:

• cross-compiles to every Go target with no C toolchain, and links into a single static binary;
• has no dependency on the Ruby runtime — the dependency runs the other way;
• can be differentially tested against the ruby binary wherever one is on PATH, while the cross-arch lanes (where ruby is absent) still validate the library itself.

See Modules for the full ecosystem index.