First of all, best direct such questions to support@marvelousdesigner.com. The below is just as I know it. Over time MD has had a number of different license policies. There was, in the days way back of MD2, indeed a restriction on commercial use. That has gone a long time ago. As far as I know the difference between a personal license and a corporate license is that the personal license is coupled to a _personal _account. Only the license holder is allowed to use it, but he can produce with it whatever he wants and do with his products as he likes. A corporate license can be used by any employee of a company and, in theory, be used 24/7. See also here There may be restrictions on distributing the demo models though.

The 'perpetual' license is a one-time payment which gives you free updates for as long as the version you have is not superseded by a later version. New versions happen to come every year, usually in October/November. LIcense updates come at very competitive rates. From the top of my head the discount when upgrading from previous version (MD8 a.t.m.) is 75% and when upgrading from next to previous and next-to-next of previous (MD6 and MD7 a.t.m.) is 60%. This means that under the current policy if you buy MD9 at 70% now (30% off), you would be good for discount on updates until MD13 is comes to replace MD12.

One thing: I put 'perpetual' between quotes because although MD does not 'phone home' you need an active internet connnnection to activate the license on your computer. You can install on as many computers as you like but you need to de-activate the license on one computer before you can use MD on another computer. Your ability to move between computers (or recover after computer deep crash) therefore depends on response from MD's license server or the kind help of their service desk. Eternity lasts for as long as these are available. However the company has existed for well over a decade now and the program has found wide acceptance so I expect the service will be around for a while.