Lam-rim is one of the most reknowned works of Tibetan Buddhism. It's composed by Tsong-kha-pa (1357-1419), a great Buddhist scholar from Tibet. Following Atisha's work, Tsong-kha-pa combined two different Buddhist ideas prevalent at the time. The Maitreya or Asanga school of Buddhism believed that the mind controlled everything. The Manjushri or Nagarjuna school believed in the Middle way and the workings of karma (cause and effect). Both schools taught to generate compassion but the way to generate compassion differred. The Mind-only school taught to look to all sentient beings as our own mother and generate compassion whereas the Middle-way taught to put ourselves in the shoes of others and generate compassion that way.

Tsong-kha-pa compiled, composed, translated, and predicted that lam-rim would be the best practise for the future. Lam-rim is basically a study of Sutra although it touches on Tantra a little at the end. More detail accounts of Tantra can be found in Nyag-rim, also written by Tsong-kha-pa.