The next evolution of Screenplay Markdown (SPMD) is out, now part of a project called Fountain. It’s quite the collaborative effort:
Fountain comes from several sources. John August and Nima Yousefi developed Scrippets, which used simple markup to embed screenplay-formatted material in websites. Stu Maschwitz drafted a more extensive spec known as Screenplay Markdown or SPMD, designed for full-length screenplays.
Stu and John discovered that they were simultaneously working on similar text-based screenplay formats, and merged them into what you see here. Other contributors to the spec include Martin Vilcans, Brett Terpstra, Jonathan Poritsky, Kent Tessman, and Clinton Torres.