Compiler design questions

The Edison Design Group (EDG) is a company that makes compiler front ends for C++ and formerly Java and Fortran.
Their front ends are widely used in commercially available compilers and code analysis tools.
Users include the Intel C++ compiler, Microsoft Visual C++ (IntelliSense), NVIDIA CUDA Compiler, SGI MIPSpro, The Portland Group, and Comeau C++.
They are widely known for having the first, and likely only, front end to implement the unused until C++20 export keyword of C++.