So, there’s already a couple of these on the web (see here, here, and here, for example). These are all great resources to browse, but it seems to me that I’m always trying to answer one question for clients as I review these resources – what do I lose by dropping down a license level? So, with that in mind, here’s my unofficial list – note that this is strictly for on-premises licensing. I’ll get around to an online version the next time I need to address that for a client. This is based on the “official” feature matrix available here: http://technet.microsoft.com/en-us/library/jj819267.aspx#bkmk_FeaturesOnPremise as of 9/20/2013. Click on any item to see more information about it.