It seems that diagram drawing has been well implemented in TeX, so we should think of what is still unsatisfactory. For instance, there is little choice of appropriate arrow tips and tails. Probably good ones could be added in the LaTeX fonts. Pino Rosolini PS I am one of the "satisfied users" of Paul Taylor's macros. The syntax they use is very simple and direct (I'd say, in the true spirit of TeX). +++++++++++++++++++++++++++++++++++++++++++