The IPMI pages are difficult to find on Supermicro's site. These are free programs that Supermicro makes available for all of their boards that have IPMI capabilities. Remember, you'll first need to go into the bios and Enable and set the IP address for the IPMI device (and hook up an ethernet cable to the port if it's a dedicated port).
There is also a JAVA web-based version that runs concurrently on that same IP address you just set in the bios (just type that into a web browser).
Default username and passwords are: ADMIN (both in all caps).
ftp://ftp.supermicro.com/utility/IPMIView/
(IPMIView is the quickest way to upgrade the IPMI firmware on your board, if it is IPMI capable)
http://www.supermicro.com/products/nfo/IPMI.cfm
(this page has all of the IPMI resources in the column on the left, as well as new versions of the IPMI firmware (if available for your board).