Is there documentation on the Ayam scene file format? How can I parse this format?
There is no documentation on the .ay file format. It is merely a serialization of the internal Ayam object structure as laid out in the file ayam.h. The Ayam team recommends against trying to convert .ay-files directly. Instead, write (better) import filters for one of the export file formats of Ayam (RIB, MF3D (Apple), 3DM (Rhino), Wavefront OBJ, X3D) for your target system, or write a new export plugin for Ayam, obvious targets are U3D, FBX, IGES, COLLADA.