The beta release includes support for a subset of the new features of MongoDB 3.6. More details on which features are available for testing can be found in the driver release notes: https://github.com/mongodb/mongo-ruby-driver/releases/tag/v2.5.0.beta
The driver is available on RubyGems and can be installed explicitly or with the '--pre' flag:
gem install mongo -v 2.5.0.beta
or
gem install mongo --pre
We invite you to try the driver in your testing environments with MongoDB's 3.6 development releases.
Please report any issues in our RUBY project: jira.mongodb.org/browse/RUBY
Thanks
The MongoDB Ruby team