Tested with ncvhdl 08.20-s004.
To compile: You will need to setup your cds.lib and hdl.var files, then create an "ieee_proposed" and "worklib" directory. Then you can just run compile.ncvhdl.
See the README for an explination of the new functions in these packages.
Notes: ncvhdl is stricter on syntax then Modeltech. It actually found a few minor things that I missed. The only error I found was in the "env_c.vhdl" file. It didn't like the 10 hr and 100 hr time resolutions.