  One aim of this note is to give an overview of some developments in the area
of Dirichlet forms. A second aim is to review the new book "Semi-{D}irichlet
forms and {M}arkov processes" by Yoichi Oshima. The book appeared last year,
but first versions were written as lecture notes 25 years ago. We first give a
rather short and light introduction into the field of Dirichlet forms with a
special emphasis on the subjects presented in the book under consideration.
After a small account on the history of Dirichlet forms we comment on the book
by Oshima against the background of related works.
