Frank, Both RZope and Rho solve this problem. RZope (http://www.analytics.washington.edu/statcomp/projects/rzope/)solves it by using *nix's fork command, which takes as much time as a memcopy. Rho(http://rho-project.org) solves it by maintaining a pool of idling R processes, which it maintains active & can pull to do a calculation immediately. Both of these are pretty immediate & allow multistep/session calculations.(As compared to CGI stuff) cheers, Nathan Here's a related question: Do any of the mentioned R-web interfaces (Rweb, R-Online, CGIwithR, RSPerl) support reusing the same R process, eliminating the startup overhead? This would be useful to me as well. Currently I use such a method on my computing cluster: All 40 compute nodes run an R process/compute server that listens at a socket for any connection and subsequent commands from another computer. When the master process disconnects, the R processes go back to listening at the socket. Connecting to the R compute servers this way takes < 2 milliseconds rather than the typical ~2 second R startup time. Thanks for any tips. -Frank ====Nathan Whitehouse Statistics/Programming Baylor College of Medicine Houston, TX, USA nlwhitehouse at yahoo.com work: 1-713-798-9029 cell: 1-512-293-5840 http://rho-project.org: rho- open source web services for R. http://franklin.imgen.bcm.tmc.edu: Shaw laboratory, bcm.