GHDL is a VHDL simulator, using the GCC technology. VHDL is a language
standardized by the IEEE, intended for developing electronic systems. GHDL
implements the VHDL language according to the IEEE 1076-1987 or the IEEE
1076-1993 standard. It compiles VHDL files and creates a binary that simulates
(or executes) your design. GHDL does not do synthesis: it cannot translate your
design into a netlist.
Since GHDL is a compiler (i.e., it generates object files), you can call
functions or procedures written in a foreign language, such as C, C++, or