i'm prepping to teach a 5-day intro class in linux starting in about 3 hours, and the courseware is clearly designed around RHEL (apparently 5.1). but since i'm not being provided with RHEL DVDs, i'm just going to hand everyone a centos 5.4 DVD and take it from there. as part of the intro, i want to briefly discuss the varieties of linux related to RHEL, so obviously i want to mention what centos is all about. in a nutshell, it's simply RHEL with any RH-proprietary branding removed, yes? what's the simplest way to sum up the difference in a sentence or two? and i've never used SL but, again as i understand it, it's also RHEL unbranded but, IIRC, SL is more open to producing updates, whereas centos is rigourous about tracking the corresponding RHEL version. does that sound about right? rday -- ======================================================================== Robert P. J. Day Waterloo, Ontario, CANADA Linux Consulting, Training and Kernel Pedantry. Web page: http://crashcourse.ca Twitter: http://twitter.com/rpjday ========================================================================