We don't have a license fee or anything like that.
Right now we're working directly with everyone in the beta to understand their process and make things work.
We've added specific features like CSS/HTML export that people wanted for their workflow, and we've also spent a lot of time on Skype with folks to help them change their "throw pictures over the wall" process to ones that help them better bring their designs to production.
You can play around with the engine in code here: https://github.com/lynaghk/subform-layout but the best way to get a sense of things is to use it from within Subform.
Curious to hear more about your use case and what you think of the existing API/demos --- definitely open a Github issue or start a topic on the Subform discussion board after you get a chance to try things out.
Right now we're working directly with everyone in the beta to understand their process and make things work.
We've added specific features like CSS/HTML export that people wanted for their workflow, and we've also spent a lot of time on Skype with folks to help them change their "throw pictures over the wall" process to ones that help them better bring their designs to production.