SWIG is a Simplified Wrapper and Interface Generator that JyMol now uses to call C/C++ functions from JAVA. This change/enhancement is not seen by the user, except for the fact that some of the functions inside the Cmd class are simpler. This is because SWIG has easy ways to pass arrays and objects back and forth between JAVA and C/C++. In the previous JyMol version, something similar to SWIG was implemented from scratch, but it was not as well polished. SWIG has a very large developer base and it makes it easier for us to provide a solid, more stable implementation of JyMol. It also makes it easier to add new functions to the interface.