So I Had a quick look at https://sciter.com/prices/ and my understanding is that it does not satisfy the "permissive open source license" criterion of my last comment. In fact, it seems that it's not open source at all (a choice that I respect, but that comes with its own set of problems, see below). In particular: the "FREE" option means Free as in free beer (i.e. zero cost), but not "FREE" as in libre: it doesn't give me access to the source code, only to "binary form as it is published on the site".
And if I want "Access to sources, 1 year", I have to choose between one of a number of commercial license options that for cross-platform (*) range from "INDIE+" (limited to "companies having three or less employees") for 620 US$ + 310$ per following year(s), via "BUSINESS+" (to escape the limit on employee count) for 2720 US$ + 1720 US$ per following year(s)… both of which still require me to mention “this code contains Sciter engine” in “about” screens or the like… a requirement which only goes away with the "ENTERPRISE++" option which is on a "Please contact us for the price" basis… as is the "OEM/FIRMWARE" option for embedded stuff.
(*) cross platform, as per https://sciter.com/sciter/crossplatform/ meaning Windows, Mac OSX and Linux / other Unixes (GTK3 based), whereas mobile OSes are mentioned as:
> "Other OSes: In principle Sciter can be ported to any OS that has graphical primitives ready. For example Sciter can be compiled to run on iOS. Or with some effort to work on Android using either existing Cairo backend or Skia graphics layer"
In our case, even aside from the the licensing and the "with some effort" for Android that makes me wary and that I can't evaluate for lack of access to the source code, It just so happens that we have a number of other libs to integrate, some of which add their own rendering (which requires access to e.g. a Vulkan context, not merely HTML/CSS or other high-level UI elements)… so that I can't justify to blindly pay that much upfront before even having a possibility to evaluate the source code first, just on blind hope, for a UI toolkit that may or may not, depending on the source code that I don't have access to otherwise, turn out to very hard or even impossible to integrate with the other libs.
> we have a number of other libs to integrate, some of which add their own rendering (which requires access to e.g. a Vulkan context, not merely HTML/CSS or other high-level UI elements)…
I have a customer that is doing something close: it is a 3D CAD alike app where they have Vulkan rendering 3D scene with Sciter UI on top of that - rendering chrome UI around that 3D and on the same Vulkan surface.
It's not at all about "labels" though (who cares), but about the very pragmatic and practical consequences, such as:
* in my comment above, the necessity of being able to evaluate whether a product is even fit for the job (which requires access to the code) BEFORE shelling out mucho money on it. Your licensing scheme is fundamentally incompatible with that pragmatic requirement, whereas open source is not. That's not a "label" issue.
* other such very practical consequences that I didn't even mention in my last comment include the following classic: when you make your product and business dependent on another (external) product, it is crucial to have some sound risk assessment: what about the bus factor of that external provider? What if they close? What if they suddenly change their licensing terms to the worse? What mess do I risk to find my business in and how hard is it to get out of that situation? With a permissive open source license, the maintained collective development can go on, whatever happens to the original developers and however they decide to change their course. With a closed license, the users and/or their businesses are doomed.
So the one part where I agree is that merely "getting the job done" for its technical part is not the ONLY thing that matters and not the ONLY relevant selection criterion. There are other very relevant and very pragmatic make-or-break criteria/issues, such as legal and business-critical questions like those that come in consequence of the license… not of their "label", but of their actual content.
It is embeddable HTML/CSS/JS/ UI layer by design.
If you want to check how it feels in real life application then check https://notes.sciter.com/ . That's monolithic, portable executable (~7mb) that includes Sciter itself and HTML/CSS/JS/ resources of the application ( https://gitlab.com/c-smile/sciter.notes/-/tree/main/src/res )