This is JRuby, not plain Ruby.

Pharohbot · on March 27, 2015

It's still the Ruby language, just a different run-time environment.

kolev · on March 27, 2015

A language without the ecosystem is just sugar.

dragonwriter · on March 27, 2015

JRuby has access to the vast majority of the Ruby ecosystem and all of the Java ecosystem.

If anything, it has a stronger overall ecosystem than MRI.

code_reuse · on March 27, 2015

the ecosystem is there, I think you're confused... the libraries work, this is the best runtime environment for a Ruby on Rails app.. which is Ruby's killer app..

kolev · on March 27, 2015

Yes, it is there, but do all RubyGems work with JRuby?

dragonwriter · on March 27, 2015

There are gems that work only with JRuby. There are gems that work with any source-compatible implementation (MRI, JRuby, Rubinius, etc.), there are gems that work with any Ruby which supports the FFI (at least, again, MRI, JRuby, and Rubinius).

There is no implementation (or implementation/platform combination -- MRI on windows supports a different set of gems than MRI on linux) that supports all gems.

kolev · on March 27, 2015

That was my point - there are two ecosystems with something shared, but you always need to be aware of the differences.

I think in the future the JVM can offer better integration with native libraries. I'm not familiar with the details, I know JNI was a pain, I know there's JNA and JNR now and I just found this: http://openjdk.java.net/jeps/191