I don't think they're talking about a released build, but rather building it yourself from source (http://madcoderspeak.blogspot.com/2009/06/how-to-compile-rub...) which is what all mac and linux users do. Even the ruby package managers we use (i.e. ruby-install, rvm, etc.) don't have pre-built binaries, they download tagged source files with checksums and run build commands.

And what has that do with the core developers? Is there a bug that prevents 2.1.5, but not 2.1.4 from running on Windows? The hostility against Windows is usually rather a community issue.

And they're not releasing pre-compiled versions for any other OS either. Build it yourself [1] or try to be patient until Luis Lavena uploads the Ruby Installer for 2.1.5.

[1] https://github.com/oneclick/rubyinstaller (edit config/ruby_installer.rb to compile 2.1.5 and not 2.1.4)