Answer: 

Intel announced the creation of an open source project (threadingbuildingblocks.org ) for Intel® Threading Building Blocks (Intel® TBB) on July 24, 2007. Until August 2016 Intel® TBB was available as an open source project under the GNU General Public License version two (GPLv2) with the (libstdc++) runtime exception.As of September 6 2016 Intel® TBB is relicensed to a non-viral Apache v2.0 license.