Acme is a programmer's text editor, shell, and user interface. It runs on a virtualized operating system, Inferno, that runs hosted on Windows, Linux, Solaris, and MacOSX.
See this video for a nice walk through of Acme: https://www.youtube.com/watch?v=dP1xVpMPn8M
You can build the limbo source tree from inside acme:
% cd /appl/
% mk install
To build the acme runtime emu follow these steps on the host command line
% ./makemk.sh
% mk install
The mk command will build all the C libraries and inferno emulator.