Ruby has many standard libraries since Ruby 1.8. We are developing them with GitHub today using default and bundled gems mechanism. I plan to continue this process for Ruby 3.4 and future versions.

However, some versions may encounter `LoadError` at `require` when running `bundle exec` or `bin/rails`, for example with `matrix` or `net-smtp`. We need to understand how they differ from standard libraries.

In this presentation, I will explain how Ruby's `require` and `bundle exec` work with default/bundled gems. I will also suggest what users can do to load them successfully.