The author here. Marta doesn't perform any network activity besides update checks, which you can disable. If you wish, you can block all network access for the application in your firewall.
The language looks really nice. I especially like its strong-typing nature. It seems, though, that it won't be easy to embed – Nim compiler requires either gcc or clang.
Well, I'm not a big fan of JavaScript :) I like the direction ECMAScript is going. However, the clumsy things are going to stay because of backward compatibility.
Also, QuickJS is a good initiative, but I afraid it's not production-ready yet. It doesn't even have versioning and/or changelog.
It seems that quite a lot of people use Lua.
I liked the language, it's tiny and well-made. However, I wasn't happy about the tooling support. IDE plugins, documentation generators, lint checkers – all of this seem abandoned.
Is there any similar language (embeddable, good C interoperability) with better tooling besides JavaScript?
You can choose what parts of the standard library scripts allowed to use. Just exclude os/debug libraries, and that's it. Newer versions of the Programming in Lua book contain detailed instructions.
Marta is not inspired by fman. The Action panel (I think it's called a Command palette in fman) is likely to be the only common thing between our products – and we both took it from Sublime Text. But it's not really important.
The "doesn't feel native" is not the main problem for me. I use a number of non-native apps (such as IJ IDEA) – and I'm okay with it.
fman is a just slow app without features. It was ok if it was in alpha stages, but why it is a paid product then? Come on, there's still no way to cancel the copy process! And you need to install a third-party plugin to swap panes. I wonder how you made such a small progress since the last year, considering that you work on fman full-time.
Well, until Swift introduces ABI compatibility, this is definitely a problem, as both Marta API and a plugin need to be built with the same version of Swift.
Depending on the Swift release roadmap, I'll postpone 1.0 until the release of Swift 5, or make the API ObjC-compatible.
I also have plans for making a "lightweight API" (possibly in Lua). It will support only the subset of features available in the "full API", but if that would be sufficient, nothing prevents it from becoming the "right" way of writing plugins for Marta. (In any case, Swift API won't disappear).
According to what I know, in case of desktop applications, the revenue drops almost to zero, unless you have a Free and Pro versions. "Free edition" then lacks almost all features that make the product competitive, and it's not really good.
It's reasonable, though, if your potential user base is totally different. For example, IntelliJ IDEA has a Community edition that lacks enterprise frameworks support, but that's not a problem for "single users" because they basically don't do any enterprise. But it looks like it won't work for Marta.
So I'd rather choose the Sublime Text strategy (though I think that Sublime costs too much).
I agree with you that the open source software has higher level of trust than the proprietary one, but I afraid I just can't maintain Marta steadily for a long time if it was open-sourced (and then forever free). And I doubt the community will do that instead of me. In case if you're interested, I expressed my thoughts about this here [1] earlier.
I do promise, though, that Marta will never collect personal data, display ads or do some other bad things. I just don't see any sense in that, and I'd rather have a good reputation.
The default key binding set is a de facto standard for double-pane file managers. I personally used Total Commander for a long time until I switched to Mac, and I really missed a FM with the similar hotkeys.
But I understand now that it's not what all Mac users expect from a file manager. I'll make an option to choose the hotkeys on the first launch [1].
As about the Touch Bar, Marta supports it since 0.1.2.
The default bindings are just a de facto standard for double-pane file managers. But all key bindings are configurable, and you can set them to whatever you want in the configuration file. Check the documentation [1] for more information.