I have a microarray analysis program using Monte Carlo Markov chain. I downloaded R 1.9 alpha and saw FOUR times increase in speed. Completelyly amazing. Specifically, one iteration takes 44 seconds under R 1.8.1 and only 10 seconds under R 1.9.0 alpha. I have averaged over many iterations so hopefully this is something real. The operating system is Win 2000 on a Pentium III 1.16 Mhs laptop. ====Jason G. Liao, Ph.D. Division of Biometrics University of Medicine and Dentistry of New Jersey 335 George Street, Suite 2200 New Brunswick, NJ 08903-2688 phone 732-235-5429, fax (732) 235-5464 http://www.geocities.com/jg_liao