My experience with this is a bit dated so maybe they fixed it since, but here goes: Gems are installed globally on your system. You need something like RVM to work around this, but oops, RVM doesn&#x27;t work on Windows and one of your devs uses that. There&#x27;s a 3-year old tutorial about how you can get it to work with cygwin, but that doesn&#x27;t work well with your favourite Ruby IDE, and the list goes on. You want to deploy to a server so you try to use bundler, but bundler hard-copies a dependency called somelib-mingw-x86 into the Gemfile.lock and your linux server chokes on that. In general, the idea that bundler makes a different dependency graph depending on the <i>OS of the dev that happens to run &quot;bundler install&quot;</i> is completely beyond my understanding.<p>I assume that it&#x27;s a bit better if all your devs (and your servers) are on the exact same OS, but compared to say NodeJS or Java, the Ruby experience is pretty messy. With Node or Java, I just say &quot;these are my dependencies&quot;, some package manager downloads them all into a <i>subdirectory</i>, and then I run the app. Done. The only global dependency is the VM itself, which is typically backward compatible so no problem there, just use the latest one. C# has it just as awesome except that some libraries were written by boneheaded Windows-only people (hardcoded backslashes in pathnames, Windows Registry dependencies, stuff like that), so in practice it isn&#x27;t as cool.