Jayaseelan et al., Natural product-likeness score revisited: an open-source, open-data implementation. In: BMC Bioinformatics, 13 (1), pp. 106, 2012.
 Peter Ertl et al., Natural Product-likeness Score and Its Application for Prioritization of Compound Libraries. In: Journal of Chemical Information and Modeling 48 (1), 68-74, 2008
NaPLeS is an open source web application based fully on open data. Source and installation instructions are available at GitHub. Please submit bug reports, feature requests and general issues through the issues tracker at GitHub. NaPLeS is developed and maintained by the Steinbeck group at the University Friedrich-Schiller in Jena, Germany.
The code for this web application is released under the MIT license. Data licenses, if available, can be obtained from the home page of the various natural product databases listed above.