Generator was designed as part of a 3rd year university project which
was written up towards the end of version 0.03 (i.e. a long time ago).
The documentation has been converted to PDF and Postscript, shown below (they're
all the same file, in different formats):
The internal fundamentals of Generator have not changed much since this
documentation was written, so you may find it interesting. There is no
need to tell me about spelling mistakes or incoherent sentences, there were
several all-nighters involved in finishing the documentation :)