Ruby Inline is an analog to Perl's Inline::C. Out of the box, it allows you to
embed C/++ external module code in your ruby script directly. By writing
simple builder classes, you can teach how to cope with new languages (fortran,
perl, whatever). The code is compiled and run on the fly when needed.

Using the package_inline tool Inline now allows you to package up your
inlined object code for distribution to systems without a compiler
(read: Windows)!

FEATURES/PROBLEMS:
   * Quick and easy inlining of your C or C++ code embedded in your ruby
     script.
   * Extendable to work with other languages.
   * Automatic conversion between ruby and C basic types
        o char, unsigned, unsigned int, char *, int, long, unsigned long
   * inline_c_raw exists for when the automatic conversion isn't
     sufficient.
   * Only recompiles if the inlined code has changed.
   * Pretends to be secure.
   * Only requires standard ruby libraries, nothing extra to download.
   * Can generate a basic Rakefile and package up built extensions for
     distribution.

WWW: http://www.zenspider.com/ZSS/Products/RubyInline/