The first type of implementation uses a BSD Sun-style loader with the -A flag to load in .o files. Usually, binaries that are to be dynamically linked must be built with the -N option. This is the older style of linking present in Ptolemy0.5 and earlier.

The second type of implementation uses the System V Release 4 dlopen() call to load in shared objects (.so files). SunOS4.1.x, Solaris2.x and Irix5.x support this style of dynamic linking. In Ptolemy0.6, only the sol2, sol2.cfront, and hppa architectures support dynamic linking of shared objects.

The interface to both styles of linking is very similar, though there are differences.