Documentation of (optional) Octave dependencies?

[Moritz Borgmann]

Does some documentation about the (optional) dependencies of Octave 
exist somewhere? I.e., information on what libraries can be used 
together with Octave, such as the BLAS implementations, sparse 
libraries, etc., and where to find them? In various files, a 
reference to INSTALL.OCTAVE is made, but this file does not seem to 
exist.

Pointers would be appreciated.

Thanks,

Moritz