Different solutions for various needs

The Free License is for non-commercial purposes only. It is a full-featured product, except that it the main component class is sealed. It gives you a single Host URL license and comes with no guaranteed support.

The Standard Edition is a commercial one developer license over a full-featured product and comes with one year of Host URLs licensing and 4 months of upgrades and support.

The Professional Edition is a commercial two developers license over a full-featured product and comes with one year of Host URLs licensing and 6 months of upgrades and support.

The Ultimate Edition is a commercial multi developer license over a full-featured product that comes with two years license for Host URLs and 1 year of upgrades and support.

Licensing and HostURLs

SilverMotion comes in four different versions, basically regarding commercial use, support period, number of licensed developers and period of HostURLs licensing.
The Free edition comes with a non-commercial license, which means it can only be used for non-profitable purposes. The Standard, Professional and Ultimate editions come with a commercial license that permits using the software for commercial and profitable purposes.
The support period is the time while PostVision grants the license holders online support on matters regarding Silvermotion.
The Free and Standard editions are licensed for one developer, Professional is for two and Ultimate - for unlimited number of developers inside the purchasing company. Only licensed developers are legally permitted to work with the purchased product.
A HostURL is the location of the Silverlight application that hosts Silvermotion. In order to run such an application from the internet, it has to be signed with the proper HostURL that corresponds to its location in the web. The Free edition gives a single HostURL, while Standard and Professionl edtions provide one year of HostURL signing and the Ultimate edition - two years of HostURL signing.