I just read about the java 2 javascript parser and the demo with scala.
Do you have any experience with this framework?
What about performance?
Can i use existing JS code/frameworks?
I appreciate any help.
EDIT
This is a very good scala to javascript cross compiler:
https://www.scala-js.org/
I did this more than a year ago. Performance is ok, but code size tends to be big. I would not recommend it for production, but can give away the code if usefull.
There are other efforts to run Scala on the browser. Best would be to create a JavaScript backend to an existing Scala compiler.
Here are some other projects to look after:
http://greedy.github.com/scala/
https://github.com/scalagwt
https://github.com/alvaroc1/s2js
https://github.com/kripken/emscripten
http://jscala.org/