Recently, I received several requests for the source code of the SCHNAaP/SCHNArP, a software package for the analysis and rebuilding of double helical nucleic acid structures. This suite of programs was developed ten years ago during my PhD work on DNA base-stacking interactions with Dr. Chris Hunter at the University of Sheffield, England.
Users become interested in SCHNAaP/SCHNArP mostly because of 3DNA, which can be taken as its superseded, more popular version. Due to Rutgers' policy of not releasing the source code of 3DNA, users who would like to understand details of the underlying algorithms thus turn back to SCHNAaP/SCHNArP. The interface is a bit aged, but the mathematics is still valid: it could serves well as a start point for those who really want to get into the world of nucleic acid structures.
Overall, though, I have a mixed feeling in this situation. On one hand, I am happy to see people becoming interested in my (previous) work. On the other hand, however, it also becomes clear that Rutgers' current licensing policy has blocked 3DNA's further circulation and adoption by the scientific community. Given the current trend of open-source software development, I see no reason to continue keeping 3DNA closed source. Making 3DNA open source (under a proper license term, of course) would allow for interested users to get more directly involved in the project, and thus to move the software to the next level.