[J.W. Bizzaro] As far as the details of network communication is concerned, Paos will be more heavily involved in this than I originally planned and should handle all the networking for us. I expect networked communication between tools to be almost identical to communication between tools on the same computer. Except the transfer of XML from tool to tool. It might make sense to make a distinction between streamed tool input and input files. If a tool has to have access to the entire result of the previous tool before it can do anything useful and the tool runs on a host that shares the same NFS with the host of the previous tool, it doesn't make sense to transfer any data: all the tool needs is a pointer to a file that contains the result of the previous tool. On the other hand, if the tool is able to process a stream of data, the entire process can be pipelined which saves a lot of time. Carlos