RxJava supports JVM languages via implementations of FunctionLanguageAdaptor
If there is a language you'd like supported please look at the existing adaptors (such as Groovy) and implement the adaptor for your language of choice.
If you feel it would be valuable for the community submit a pull request and we'll accept it into the main project.
Please comply with the conventions established by the existing language adaptors if you intend to submit a pull request.
NOTE: Changes are coming in regards to static and dynamic typing and how language adaptors are used.
See ReactiveX#208 and ReactiveX#204