For this task you will need a C compiler, the gunzip/gzip program, the tar program, the make program and the patch program (should you wish to install the patches -- and you really do). These are standard on most Unix-like systems. You will also need to select the appropriate HOST Makefile -- see doc/Platforms for more information on selecting the appropriate HOST setting for your machine. If you do not have one or more of these tools, the excellent GNU versions are available for almost any flavour of Unix (plus a few other platforms) from the main GNU ftp site or any of its many mirror sites.
DGD is known to compile on Windows 95/NT using MSVC++ 4.x and better. It should be noted, however, that while this compilation works out of the box with MSVC++ 4.x, users of 5.x and later will need to turn off optimizations in the supplied project file. DGD source has also been compiled on Windows 95 with gcc from the Cygwin tools (beta 20.1 version) using a HOST configuration of LINUX and replacing src/host/lrand48.c with src/host/pc/local.c. One suspects it would also compile with the Borland compiler as well, although there are no reports one way or the other on this.
If you are using OS X you can compile the unix source code if you have the Mac Dev Tools. One user points out that you may run into trouble with the ones prior to 10.2 (Jaguar) due to missing support for random().