What mod or hack ?

Could someone tell me what hack vBSEO use to add the Digg, Technocrati , dl.ici.us link (see attaced image) to every post on this site.
Thanks

Hello,

this is one of vBSEO features ("Social bookmarking" option in vbseocp)

Thanks very much, I will enable it in my vBSEO righ ways, should have read the manual thorougly