dmd -o- -Dddoc *.d
Just compile all of the .d files into a .lib (Windows) or .a (Posix) file. Build command for the GTK port:
dmd -lib -ofplot2kill.lib -O -inline -release *.d
If you're using DFL, add -version=dfl to the build command:
dmd -lib -ofplot2kill.lib -O -inline -release -version=dfl *.d
To build the demo/test module and compile an executable instead of a library, do:
dmd -O -inline -release -version=test *.d
or
dmd -O -inline -release -version=test -version=dfl *.d
Plot2Kill is licensed under the Boost license. You may not be able to use it under such permissive terms if you link to a copylefted GUI library. For example, GTK and gtkD are LGPL, which adds some (minor) requirements to executables that link to it, but imposes no burdens on source code that simply refers to the LGPL'd library. (The sources to this project, in isolation, would be considered a "work that uses the library" and fall outside the scope of the LGPL.)