> The short answer is that not only would I like to be able > to add extentions that sit on top (at the AbstractNetcdf > level) but that also build from the lower level concrete > implementation without pushing the low level implemenation > around, and without haveing to encapsulate all the functions > that it implements. Dan: We have dropped the 'final' designator from Class ucar.netcdf.NetcdfFile. There is a new release, tagged ucar19981019, at the ftp site, which includes this change and some bug fixes. Have fun. -glenn