Bill Kelly wrote:
> (Note, I don't have any vested interest in this, I am merely quoting 
> from the IRC logs... For example, I don't
> know why it was important to find the current running
> binary.  But I'm not sure how RUBY_ENGINE was supposed
> to help in the ../../blah/bin/ruby situation anyway? :)

Say you have a library written in C for MRI, modified C or Ruby with 
Rubinius features on Rubinius, or using Java in JRuby. It would be much 
nicer to be able to do:

require "my_library/platform/#{RUBY_ENGINE}_api"

Rather than a series of if/else checks that use a combination of 
variables. As much as Rubinius, JRuby, MRI, IronRuby may look the same 
as far as normal Ruby code, there are differences in how they integrate 
with the underlying platform and differences in how you may want to use 
them. And currently there's no simple way to definitively know which 
Ruby implementation you're using. RUBY_ENGINE is just one constant that 
will solve that problem forever...I'm not sure why there's so much 
resistance to adding it.

- Charlie