Madhyamaka
Madhyamaka (Sanskrit: मध्यमक, Madhyamaka) refers primarily to a Mahāyāna Buddhist school of philosophy founded by Nāgārjuna. According to Madhyamaka all phenomena (dharmas) are empty (śūnya) of "nature," a "substance" or "essence" (svābhāva) which gives them "solid and independent existence," because they are dependently co-arisen. But this "emptiness" itself is also "empty": it does not have an existence on its own, nor does it refer to a transcendental reality beyond or above phenomenal reality.
Great Madhyamaka
In Tibet, there is a school known as the Great Madhyamaka, or Yogacara-Madhyamaka, known as Shentong. Practitioners of this school claim this is a superior view to the ordinary Madhyamaka. This view was elucidated in the scriptures of Maitreya, Asanga, Vasubandhu and Dignaga. It was also profoundly illuminated in Nagarjuna's Praise to Dharmadhatu. Thus, Shentong is considered to be the viewpoint of both masters, Nagarjuna and Asanga.