I am trying to get Ruby syntax highlighting and code folding to work with
gnu emacs. I've loaded the necessary .el files (ruby-mode, inf-ruby,
rubydb3x). Turned on syntax highlighting (Global font lock mode).

But I cannot get
- *.rb files to automatically enter Ruby mode
- syntax highlights (after I manually set ruby mode)

Separately, is there any code-folding (major or minor) mode available?

Any pointers appreciated.

Thanks