Complex sentence: Earlier versions of RhodeCode Enterprise were licensed entirely under the GNU General Public License version 3, but in August 2013, RhodeCode 2.0, introduced exceptions for parts of the software distribution.
Split into simpler sentences: Earlier versions of RhodeCode Enterprise were licensed entirely under the GNU General Public License version 3. But RhodeCode 2.0, released in August 2013, introduced exceptions for parts of the software distribution.