>      I think I understand what you are saying but I am not sure. Could you 
>      give me a description of what you mean by "parameterized mixin" or 
>      provide a URL for a site. It is not a term with which I am familiar.

Analagous to a Template, but in my case perhaps more analogous to
a macro expansion.  However, neither of these would cover variations
in implementation, but would take care of such things as variable and
method names.

Variations in implementation starts getting into a somewhat more involved
discussion.  Essentially, it is a recognition that there are usually several
ways to achieve a certain goal, hence various means of resolving the conflicts
of a Pattern ( in the Alexandrian sense ).  So a means of accomodating and
managing those variations is needed, along with a means of composing patterns
from other patterns, optimising the shape of a pattern to best fit a particular
problem but according to the rules governing a pattern,etc.

Which is to say that at this point it is for me the beginnings of some notion
about a way of doing some things... It gets involved. To describe it better,
I'd have to build it.  This is only one of many things I would like to do,
but never seem to get around to doing them.  Rather aggrevating, actually.

les