What are the default gems of Mac OSX 10.11?
<p>I tried to study Ruby on Rails and followed a tutorial. However, I think I missed a part and I can't proceed to the next step in the tutorial, so I plan to uninstall things, including the gems I installed, and start all over again.</p>

<p>I installed Ruby using Homebrew, because people say it's best not to mess with the Ruby that comes with macOS. Then, I uninstalled it again using <code>brew uninstall ruby</code>.</p>

<p>After doing that, I ran <code>gem list</code> and this came out:</p>

<pre><code>*** LOCAL GEMS ***

- bigdecimal (1.2.0)
- builder (3.2.2)
- CFPropertyList (2.2.8)
- io-console (0.4.2)
- json (1.7.7)
- libxml-ruby (2.6.0)
- minitest (4.3.2)
- nokogiri (1.5.6)
- psych (2.0.0)
- rake (0.9.6)
- rdoc (4.0.0)
- sqlite3 (1.3.7)
- test-unit (2.0.0.0)
- thor (0.19.1)
</code></pre>

<p>What are the gems (if any) that come with macOS system Ruby?</p>