Zortech C++ 3.04: const doesn't work correctly with this compiler, so the package skips all of the statements Zortech can't handle. Zortech leaves rubbish on the heap. I don't know whether this is my programming error or a Zortech error or additional printer buffers. Deactivate the option for version 2.1 in include.h. Does not support IO manipulators. Otherwise the package mostly works, but not completely. Best don't #define TEMPS_DESTROYED_QUICKLY. Exceptions and the nric interface don't work. I think some of the problems are because Zortech doesn't handle conversions correctly, particularly automatic conversions. But, also newmat is just too big for my version of Zortech. Zortech runs much more slowly than Borland and Microsoft. Use the large model and compile as much as possible with optimisation on to save space. You won't be able to get the whole test program to work. Zortech doesn't have io-manipulators so you can't compile the example.
I haven't tried the Symantec successors to Zortech.