Yes, Desktop builds are on the roadmap. We don't have a fixed release date for those yet. An experimental macOS build is already available in the mainline repo.
Shameless plug: We're developing the Boden Framework [0] which kind of shares that vision.
I like the idea of a protocol and that is pretty much what Boden attempts to achieve in the end. Having said that, the more I work on this project the more I come to believe that, at a certain point (level of detail), attempts at the unification of real native UX on different platforms become virtually impossible. To achieve real native cross-platform UX, you need to embrace and take care of the different aspects, behaviors, and quirks of each platform. Boden attempts to make that as easy as possible (and without forcing you to write JS).
If the app is open source (or at least the source code is accessible), the user would proceed to the source repo, clone it, open the Xcode project and relink to the framework version of their choice.
Others have pointed out how it could work with closed source apps. It's a bit more complicated, but it certainly is possible.
We have put a lot of effort into investigating and assessing different licensing options. There are two different perspectives on this: the user perspective where MIT of course seems to be among the most attractive ones at first glance. Then, there's the company perspective: what is the business model and how is development going to be sustainable in the long run?
We have come to the conclusion that LGPL is currently the best option to align both of these perspectives and provide the best value in the long run.
If GPL/LGPL isn't sufficient for you, we'll be offering a commercial license with fair terms as an alternative.
Please take the following with a grain of salt. I am not a legal expert, but we have competent US lawyers assessing this for us right now.
The main issue we see with the GPL is that your app has to be effectively licensed under the GPL too, which makes your app's license incompatible with the iOS App Store's terms of service.
This is apparently not the case with the LGPL. Yes, you will have to provide a way for users to relink your application to another version of Boden. As far as I can see (I am not a lawyer), this can happen outside of the iOS App Store.
Our US lawyers are currently investigating this. As soon as we get a reliable assessment from the legal experts, we'll add an LGPL option to Boden.
Sorry, I should have written "apps conforming to the terms of the LGPL" instead of "free". Of course it's still possible to sell apps based on Boden licensed under LGPL as long as you comply with the license terms.
There is already an experimental macOSX port in boden. More desktop support is a future goal. The library is designed to support all types of operating systems.
Author here. We didn't expect so much attention and are happy about the feedback! Ask us anything.
With regard to the GPL licensing issues brought up here: We are aware that the GPL is not sufficient and we are in the process of adding an LGPL option. This will allow you to publish apps based on Boden on the iOS app store.
Boden author here, a bit overwhelmed by the feedback. We are in the process of releasing a new version that will change the license to LGPL / Commercial.
Author here. We’re still in the process of figuring out what the right open-source licensing model for Boden should be. In the long run, development must be financed by a viable business model as Boden is not a hobby project. We’re considering adding a commercial option later, ending up with a dual GPL/commercial license similar to other projects. We’re happy to hear your thoughts about other licensing options!
Author here. The goal of Boden is very much that the applications should look and feel as if they were custom-coded for the specific platform. We also think that custom widgets often fall slightly short of the native feel, as other commenters have pointed out. While it is certainly possible to make them 100% consistent with other native apps on the platform, it is a lot of work to get all the details right. And not all frameworks manage to do that.
We wanted to try a different approach. Why not just use what the platform gives you and always get the right look & feel out of the box? That certainly creates its own challenges, like having to provide a good abstraction layer for the core application code. But you do not have to worry about look, feel, drawing performance, interactions with other OS features and the like. And when the OS changes something then the app is automatically up-to-date.