if you want to know network card vender by MAC address .MAC address first 16 bit is assign to vender OUI code .
Search your MAC address starting 16 bit below link
http://standards.ieee.org/develop/regauth/oui/oui.txt
VMware uses the Organizationally Unique Identifier (OUI) 00:50:56 for manually generated addresses
Xen project uses the Organizationally Unique Identifier (OUI) 00:16:3e: for manually generated addresses