It looks like it is open source, but I feel that the structr.org website should talk more about the open source project, and a structr.com website should focus on the business. Right now, looking at structr.org, I don't see anything about the open source project. It just looks like a sales pitch to me.
It is open source, and we changed the frontpage to make it more clear.
Regarding structr.org/structr.com, I agree. We will make structr.com the commercial site in the future while turning structr.org into a site for the community.
And on the sales pitch: It's somewhat intended as we need some commercial customers from time to time, not being backed by big investors.