To compile and run on macOS:
Install XQuartz:
$ brew cask install xquartz
Then run it from the terminal: $ open /Applications/Utilities/XQuartz.app
Clone libschrift from Github, then edit the file config.mk and update lines 14 and 15 as follows: X11INC = /opt/X11/include
X11LIB = /opt/X11/lib
Then compile and run the demo: $ make
$ export DISPLAY=":0"
$ ./sftdemo
You should see a "Hello world" app.