My talk about what is jruby, how it works and why i find it very interesting. Also it's about how you can try it today, what are the main advantages of using it and what difficulties you can face

1. WHAT IS JRUBY?
... AND WHY I LIKE IT :)
/BalazsVarga @vbalazs

2. "JRuby is a100% Javaimplementation of the
Ruby programming language. Itis Ruby for the
JVM."

3. MIXED MODE ENGINE
Interpreter + JRubyJIT
AOT-compiled to Javabytecode
JIT:JustInTimecompile
AOT:Ahead-of-timecompile

4. JIT ALL THE THINGS (J.A.T.T ©)
JIT:JustInTimecompiler

5. HOW CAN I USE IT?
rvm installjruby
rbenvinstalljruby-X.Y.Z
$ruby-v
jruby1.7.11(1.9.3p392)2014-02-2486339bbon
JavaHotSpot(TM)64-BitServerVM1.8.0-b132+indy[darwin-x86_64]
$ruby-e"puts'hello'"
hello

6. HOW ABOUT WEBAPPS?
Embedded servers mostlybased on Jetty, Tomcat, JBoss and
Vertx (ex.: Puma, Trinidad, TourqueBox)
run with the server from the project
package in ajavaarchive (jar) and execute as ajavaapp
Standard javaservers like Jetty, Tomcat, JBoss, GlassFish,
WebLogic
Phusion Passenger (>=4.0) :)
Differentfeatures and performance butyou can easilyswitch
between them.

7. PERFORMANCE
JRuby: interpreted or AOTmode
JVM: clientor server mode
JIT:JustInTimecompiler
AOT:Ahead-of-timecompiler

8. THREADS & CONCURRENCY

9. THREADS & CONCURRENCY
Rubythread == Javathread == native thread
No GIL
Runtime is threadsafe (exceptsome core classes)

10. STARTUP TIME
Performance trade-off

11. DEBUGGING
Itworks :)

12. C EXTENSIONS, INCOMPATIBILITIES
cannotrun native C extensions
ActiveRecord-JDBC adapter (extension)
FFI ftw
FFI:Foreignfunctioninterface

13. FUTURE - TRUFFLE
experimentalimplementation usingGraaland Truffle
Graalis anew implementation of aJITcompiler in the
OpenJDK JVM
expose VM functionalityviaJavaAPIs
Truffle: AST(AbstractSyntax Tree) interpretingframework
SimonyiConference 2014
15 April2014
http://konferencia.simonyi.bme.hu

14. FUTURE DEVELOPMENT
https://github.com/jruby/jruby/wiki/SuccessStories
Sponsors over the years:
Sun Microsystems
ThoughtWorks
Engine Yard
RedHat(from 2012)

15. SUMMARY
Disadvantages
Slowlyfollows the Rubylang.
Incompatibilitywith C exts
Fewer developer
Advantages
Integration with Java
Performance
Brightfuture

16. QUESTIONS?