This article is from the Magick Tantra FAQ, by Tyagi Nagasiva firstname.lastname@example.org, Catherine Yronwode email@example.com with numerous contributions by others.
Generally tantric yogis or yoginis are Hindu, and by this
generalization we may presume that they accept a cosmology
or have been assimilated by a culture which is Saivite,
Saktiite, or, in some unusual cases, Vaisnavite. Some
schools of Buddhism (but by no means all) endorse tantra
yoga or tantric practices; this is especially true in
Tibetan Buddhism. In addition, there are Taoists who
incorporate tantra-like disciplines into their teachings,
although they are not likely to use the term "tantra."
It is assumed by most scholars that both the Buddhist
and Taoist forms of tantra derived from Hindu sources
centuries ago. However, with the popularization of books
as sources of mystical disciplines, it is possible that
some of the instructions provided by these cultures may be
followed by interested people quite outside Hindu, Buddhist,
or Taoist traditions.
For a comparison between Hindu and Buddhist tantra yoga and
the sexual mysticism of other cultures, see also