I talked about ((<"Goodbye fat gem"|URL:https://rubykaigi.org/2020/presentations/ktou.html>)) at RubyKaigi Takeout 2020. Fat gem is a gem that includes pre-built binaries. Extension libraries can assume that users have build environment with Ruby 2.4 or later. So gems don't need to bundle pre-built binaries for easy to install. Users can build binaries by themselves. As of 2025, we're still using fat gem... I discussed how to improve this situation with ruby-installer author, Nokogiri maintainer and RubyGems community in 2022: * ((<"[RFC] Allow specifying and installing external dependencies"|URL:https://gist.github.com/postmodern/4c0cbccc0c7eda4585db0fc5267cdd57>)) * ((<"Standardize +requirements+ field from the specification rubygems/rubygems#1296"|URL:https://github.com/rubygems/rubygems/issues/1296>)) I propose a solution based on these discussions.