STK++ <http://www.stkpp.org> is a collection of C++ classes for statistics, clustering, linear algebra, arrays (with an Eigen'-like API), regression, dimension reduction, etc. The integration of the library to R is using Rcpp'. The rtkore package includes the header files from the STK++ core library. All files contain only template classes and/or inline functions. STK++ is licensed under the GNU LGPL version 2 or later. rtkore (the stkpp integration into R') is licensed under the GNU GPL version 2 or later. See file LICENSE.note for details.