Simply type:

make

This will build the program (should work on most recent Linux distros and FreeBSD 5.x/6.x)

Note that the wstart program must be run as root (or effectively as root with sudo or by
setting the program setuid. I don't do this out of the box, since it's a bad idea to
setuid programs unless you know what you're doing and want to take that risk.

You can then optionally create a configuration file (wdiag.conf) in either /etc or
/usr/local/etc. An example is included in the examples directory.
