DAXCAD is a Fortran based CAD package from the 1980s
It has a wiki entry and you can read it here:
Most of the code is Fortran 77 - some bits are C - its a mixture. The code was originally written for an Apollo Aegis platform and used Apollo GPR. You can google that. It was then ported to a PC and used PC based device drivers and a Pharlap Extender.
The code was also ported to a Sun OS by a partners company and this is the main version here although 98% of the original code was still based on Apollo
In order to port to XWindows - a GPR emulation library was written called GPRX and thats also used here to provide X Window capability
CAD was expensive in the 80s - DAXCAD made it accessible - AutoCAD did it better - but then they had like way more people.
With eclispe you can import this from git and just clone - general project You need to install CYGWIN on Windows Ensure you have gcc and gfortran run make from the daxcad dir ensure that the daxcad.4.0 directory is eithr copied or linked to /daxcad.4.0 in your path then run ./daxcad from a cygwin session
I use xming and that works pretty well
CYGWIN has its own Xserver - just type xstart at the command prompt
A few good people did DAXCAD and given the relativley small number back in the 80s it was a pretty good job
Fork away if you want or let me know and you can be an admin.
This was a private company but it went bust and the code has passed into the public domain