See the "Getting Started" section of the manual,
doc/manual/getstarted.html

To see the demoes, change to the demo/xxx directory, run make and then
demo, like this:

	cd demo/oven_gtk    # replace with whichever demo you want
	make
	./demo


What do I need to compile MAT?

See the "System Requirements" section of the manual,
doc/manual/requirements.html

Of the more unusual stuff, you'll need the GTK Extra development and Comedi
development files. In Debian, these are libgtkextra-dev and libcomedi-dev.

(If you don't want to use comedi, you can just comment that part out of the
main Makefile.)