rubygems

/rubygems/

Ruby gems, without touching a single Gemfile

Point your client at it

bash

bundle config mirror.https://rubygems.org http://HOST:10220/rubygems

Replace HOST with your mirror’s address. Port 10220 is the server’s default.

Upstream: https://rubygems.org
What is stored: Gems in the blob store and catalogued; compact-index files on local disk.

How it works

Bundler resolves against the compact index — /versions and /info/<gem> — rather than downloading a full dependency graph, and that is what LibWorld serves.
A .gem file cannot be replaced once pushed, so gems are cached permanently on first fetch.
This one is configured as a Bundler MIRROR rather than as a source, and that difference is worth having: your Gemfiles go on naming rubygems.org exactly as they do today, so nothing in any repository has to change and nothing has to be changed back if you stop using the mirror.

Things that have cost real time

Written down because they were paid for once already.

One ecosystem, four metadata shapes, because RubyGems kept the old ones working: the compact index (/versions, /info/<gem>), the legacy specs*.gz, and the marshalled gemspecs under quick/. All of them are mutable and revalidated; the only cache-forever artifact is the .gem itself.