If you plan to use OpenACS for on-line communities, then you almost certainly will have to learn how to work with AOLserver. But even if OpenACS does not interest you, AOLserver's flexibility, speed and multithread capabilities are well worth investigating for your dynamic web sites.
Reuven M. Lerner is a consultant specializing in web/database applications and open-source software. His book, Core Perl, was published in January 2002 by Prentice Hall. Reuven lives in Modi'in, Israel, with his wife and daughter.