Yes. CRAN R is licensed under the GNU General Public License (version 2). As permitted under that license, Revolution R Enterprise is based on a modified version of CRAN R. The source code to that modified version (including a list of changes) is available for download when you download the binary version of Revolution R, as required by the GPL.
As an open-source company, Revolution Analytics respects the Free and Open Source Software philosophy and respects all free-software licenses. Revolution Analytics is also a direct supporter of the open-source R project: financially (as a benefactor of the R Foundation), organizationally (by sponsoring events and user group meetings), and technically (by contributing or modifications to CRAN R back to the community).
As an open-source company, Revolution Analytics respects the Free and Open Source Software philosophy and respects all free-software licenses. Revolution Analytics is also a direct supporter of the open-source R project: financially (as a benefactor of the R Foundation), organizationally (by sponsoring events and user group meetings), and technically (by contributing or modifications to CRAN R back to the community).