Interix
Gentoo/Interix (eprefix) is a port of Gentoo that runs atop the Interix Subsystem for Windows which is also known as Microsoft Windows Services for UNIX (SFU) or Subsystem for Unix-based Applications (SUA).
A result of the Gentoo/Interix project is the ability to install and use the Portage system to emerge native Windows applications (requires Visual Studio, 2008 Express Edition will do too). However, this feature does not support the wide variety of packages supported by other platforms (including Interix).
Read more about this topic: Gentoo/Alt, Gentoo Prefix