Unfortunately, this project is effectively dead and has been for a good number of years, so it has not been maintained and is unlikely to build with modern tools.
The Download page content has been restored, however, note that the project has been inactive for years.
There are some (probably quite a few) changes in the Subversion repository since...
GLWXDriver2D building
Fix applied (untested since I'm not in a position to do so presently) as r40280.
GLWXDriver2D: fix compilation error