Is Ruby as cross-platform as Java?

Ruby is a scripting language and it is interpreted at the run time by the Ruby interpreter , The Ruby code is interpreted and converted to machine level language i.e Assembly code . Talking about the platform Independence you can run ruby code in any of the the platform like Linux ,Windows or Mac if you have platform dependent Ruby Interpreter installed.

Where as in Java , it is Compiled and converted to an intermediate byte class and this byte class is interpreted by platform dependent JVM (Java Virtual Machine ) .

In that way you can think you Ruby source file as byte class which can be run on any platform ,with one difference byte class is already compiled but ruby source file will be compiled at the Run time .

Ruby binds fairly closely to the underlying platform. This is especially the case when it comes to process/threading mechanisms, and various forms of IPC. These are more significant challenges to overcome, compared to "trivial" ones as directory seperator, and so forth. I'm pretty sure that there isn't parity between, say, the Windows Ruby runtime and the Linux Ruby runtime.

With Java, the IPC/process/thread model is the same on all platforms that runs the JVM.

Java is cross platform. Ruby is not. It very much feels like an afterthought of, "oh we have windows users, let's try and get it working".

In Java I have experienced less than 10 cross platform issues in years of heavy use. The areas that this was in, were obviously areas that would be tricky. System/File system specifics.

In ruby, I've experienced problems even when doing the first rails tutorial as have others (https://github.com/twbs/bootstrap-sass/issues/696) . I wouldn't consider ruby cross platform. The platform relies on a whole host of dependencies, which anytime one of them uses anything platform specific the whole thing breaks. i.e. see this error:ExecJS::RuntimeError on Windows trying to follow rubytutorial

I also inherited a largish ruby project and it relied on capistrano, webkit, bcrypt and these needed a dev build kit and native builds. It did not just work. See the people having trouble here:https://github.com/codahale/bcrypt-ruby/issues/116It's funny, at one point they suggest someone follows a japanese post :)