In many terms, WebSolver is just another Java-based and WWW-based metacomputer collecting and exploiting world wide unused CPU-time, in many other it is not. WebSolver does not only provide an agent-based system for distributing computations over the www, it also accepts computation jobs submitted from all over the world via a www interface. WebSolver deals with problems like platform differences, dynamic topology changes, latency and fault tolerance, security, data and problem partitioning, and communication models. Our project defines a set of problem categories, each with support in the system, making programs easy to implement rapidly. This makes WebSolver not only an efficient system for solving large and resource-demanding problems, but also a valuable tool for algorithm design and parallel program prototyping.