Just in time for your holiday hacking, the RubyInstaller for Windows
project  is pleased to announce its latest release of the DevKit 
providing MinGW GCC v4.5.1 capabilities for Ruby on Windows users.
The DevKit is a powerful compiler toolchain focused on making it easy to
use, build, and develop native RubyGems on Windows platforms. Since the
DevKit is used to build the MRI-based RubyInstaller and it’s required
native dependencies, it’s an integral component of the RubyInstaller
project. Many RubyInstaller users have also discovered the DevKit is a
useful toolchain for building other native projects on Windows.
While the DevKit will remain primarily a foundational build toolkit,
expandable to meet your unique needs, it will continue to be enhanced
for functional and ease-of-use reasons. Enhancements in this version
- default toolchain is now TDM-based gcc/g++ v4.5.1
- enhanced installation and upgrade behavior
- easier 3rd party integration
- initial support for JRuby cext (C-extensions) , , 
- expanded core functionality (libtool, automake, mintty)
- modularized build recipes for building TDM, TDM 64-bit, and LLVM-GCC
…with the full list and usage instructions available at .
== QuickStart ==
After installing/upgrading  you may want to use a native RubyGem such
as RDiscount. Simply type “gem install rdiscount --platform=ruby” and
have at it.
Or you may want to build the latest EventMachine code from your cloned
repo. A “rake -rdevkit clobber compile” from your repo root dir should
get you going.
Or maybe you’re developing a native RubyGem and want to manually build
the native extension. Type “ruby -rdevkit extconf.rb” and you’ve got
Or maybe you’d like to try building another native package from source.
Something like “c:\devkit\devkitvars.bat” (or “c:\devkit\devkitvars.ps1”
for you PowerShell users) will bring all the DevKit tools onto your
PATH, ready to help you build the code.
Or maybe you’d like to build  your own self-extracting DevKit, say an
LLVM-GCC v2.8 32-bit version. No problem. Simply clone the
RubyInstaller repo and…
C:>git clone git://github.com/oneclick/rubyinstaller.git
C:\rubyinstaller>rake devkit sfx=1 dkver=llvm-32-2.8
However you decide to use the DevKit, we hope you find it makes your
Ruby on Windows experience a lot more rewarding and productive.
If after reading the documentation you run into problems or have
questions, drop by our helpful and friendly Google Group at