Ruby Gems is powered by Roda, Sequel and several other ruby gems:

Name Version Summary
bundler 2.1.4 The best way to manage your application's dependencies
concurrent-ruby 1.1.6 Modern concurrency tools for Ruby. Inspired by Erlang, Clojure, Scala, Haskell, F#, C#, Java, and classic concurrency patterns.
connection_pool 2.2.2 Generic connection pool for Ruby
daemons 1.3.1 A toolkit to create and control daemons in different ways
did_you_mean 1.2.1 "Did you mean?" experience in Ruby
erubi 1.9.0 Small ERB Implementation
eventmachine 1.2.7 Ruby/EventMachine library
hamster 3.0.0 Efficient, immutable, thread-safe collection classes for Ruby
json 2.3.0 JSON Implementation for Ruby
link_header 0.0.8 Converts conforming link headers to and from text, LinkHeader objects and corresponding (JSON-friendly) Array representations, also HTML link elements.
mini_portile2 2.4.0 Simplistic port-like solution for developers
net-http-persistent 3.1.0 Manages persistent connections using Net::HTTP plus a speed fix for Ruby 1.8
nokogiri 1.10.9 Nokogiri (鋸) is an HTML, XML, SAX, and Reader parser
rack 2.2.3 A modular Ruby webserver interface.
radiodns 0.1.3 Perform RadioDNS resolutions and service lookups
rake 13.0.1 Rake is a Make-like program implemented in Ruby
rdf 3.1.1 A Ruby library for working with Resource Description Framework (RDF) data.
roda 3.30.0 Routing tree web toolkit
roo 2.8.3 Roo can access the contents of various spreadsheet files.
rubyzip 1.3.0 rubyzip is a ruby module for reading and writing zip files
sequel 5.31.0 The Database Toolkit for Ruby
sparql-client 3.1.0 SPARQL client for RDF.rb.
sqlite3 1.4.2 This module allows Ruby programs to interface with the SQLite3 database engine (
thin 1.7.2 A thin and fast web server
tilt 2.0.10 Generic interface to multiple Ruby template engines
titleize 1.4.1 Adds String#titleize for creating properly capitalized titles.
yajl-ruby 1.4.1 Ruby C bindings to the excellent Yajl JSON stream-based parser library.