To install CocoaPods you can run:
$ [sudo] gem install cocoapods
To enjoy performance benefits you can install a modern Ruby like 2.0.0 through a
Ruby version manager like RVM. If you are using RVM, or equivalent, we suggest not using sudo as it may have some unintended effects on other parts of your system.
To update CocoaPods you can run:
$ [sudo] gem install cocoapods
If you would like to try a pre-release version of CocoaPods you can run:
$ [sudo] gem install cocoapods --pre
The gem might not be able to compile, to solve this you might need to symlink GCC.
If you used an pre release version of Xcode you might need to update the command line tools.
CocoaPods is not compatible with MacRuby.