David Kaplan is the author of Five Approaches to Acting (2001, 2007) which describes the provenance and practice of onstage performance. In his own practice, he directs plays and teaches classes around the world. He pursues projects over decades. In 1997 he began research on what would become, in 2016, a concert-party version in Ghana of Tennessee Williams' Ten Blocks on the Camino Real. As part of the process in 2012, he staged a marketplace version in Paysandu, Uruguay in Rioplatanese Spanish. Other texts directed by David Kaplan putting theory into practice that refines theory include a Sufi King Lear in Tashkent, Uzbekistan, performed in the Uzbek language; Genet's The Maids in Ulaan Baator, Mongolia, performed in Mongolian; A Midsummer Night's Dream in Buryatia, performed in the Buryat language with shamans. In Russia, Mr. Kaplan staged the first Russian-language productions of Auntie Mame and Tennessee Williams' Suddenly Last Summer.

Also in Russia, in Russian: Macbeth and Eugene O'Neill's Ah, Wilderness! At the Hong Kong Repertory Theatre he has staged Tennessee Williams' The Eccentricities of a Nightingale and Edward Albee's Three Tall Women, both in Cantonese. He has directed performances seen in forty of the fifty United States.In September 2015 a collection of his essays written over a decade was published under the title Tenn Years: Tennessee Williams On Stage. He is also the author of the biography Tennessee Williams in Provincetown and the photo essay Lorca in Lubbock, accompanying photographer Ride Hamilton's documentation of Kaplan's production of Lorca's Doña Rosita performed in a backyard in Texas by children and adults. He has taught at Clark, Hofstra, NYU, Columbia, Rutgers, The University of New Mexico, The University of the South, Mississippi State University, The Siberian Academy of Fine Arts (in Russian), the Hong Kong Academy of Performing Arts, Bilkent University in Ankara Turkey, Actuando sin Actuar in Mexico, the Metodi Festival in Italy, the William Esper Studio and the Lee Strasberg Institute.