Maybe you want to read their crowdfunding page and homepage, because not being an android phone is the point from the start, so I'm not sure why you seem surprised :)
It's not the first attempt, either. Before them, there has been (in no particular order) firefox OS, ubuntu phone (Unity was initially meant as a "responsive" environment for mobile, laptop and desktop), QT mobile and maybe others. For a long time, opensource leaders wanted to build a "true" linux mobile OS, this is just a new step on that road, and I hope this will finally be a successful one.
I'm not sure why you consider it to be an impossible challenge, the hard part in building a new OS was building its kernel and coreutils, and this has been solved for about 30 years. Now, it needs to be adapted for mobile specificity.
That's the point. No Android. They aren't going to make a whole new OS, they are using Linux but with conventional glibc and graphics stack (Mesa / Wayland). They are relying on Etnaviv: https://github.com/etnaviv
That's a good thing. There is more than enough Android around already, we need proper Wayland based mobile Linux with open drivers, that also works on a decent usable device (and that it's privacy respectful is a huge bonus too).
Jolla for example never opened up their SailfishOS despite multiple promises (it's just too hard and not a priority for them). So Librem 5 can be that option at last.
Would love to see OSes based on KDE Mobile or whatever it is called these days. Qt is a solid framework.
Fairphone Open [1] for FP2 is based on Android but completely open source. You can run it with GCM (which isn't open source) or without. You can run LineageOS (with or without microG), and there are unofficial ports of Ubuntu Touch and SailfishOS. The phone is also modular though the hardware is slightly out of date for 2018 standards.
> Would love to see OSes based on KDE Mobile or whatever it is called these days.
Purism said, they are working with KDE developers to support Plasma Mobile on Librem 5.
I wish though Plasma Mobile would get rid of those archaic on screen buttons, and would adopt SailfishOS style swipes navigation. Or at least they should make that an option. KDE is after all well known for customization.
> I wish though Plasma Mobile would get rid of those archaic on screen buttons, and would adopt SailfishOS style swipes navigation. Or at least they should make that an option. KDE is after all well known for customization.
I wish they won't, as it's hard to get right. In my personal opinion the Sailfish swipe UI was one of the probable reasons it failed in the market -- it was hard to explore, and error-prone to use.
Meanwhile the N9 swipes felt just right to me, so I think it's about having enough UX expertise at the design team. Which open source projects famously are short of.
Make it configurable, so users would be able to assign actions to any swipe and gesture. That should allow customizing it to your needs any way you want.
That works for technically oriented people, so maybe in this case it'd be fine. But in general configurations are avoided in end-user applications for a good reason, as they increase complexity both for developers and users.
Whilst I understand the need to make some bespoke UI components, I hope they don't get too much not-invented-here syndrome.
OpenMoko went down that route: the Freerunner shipped with a bespoke GTK UI (with support from Gnome; I seem to remember them being at GUADEC) but they'd already deprecated it in favour of a bespoke EFL UI. This meant a huge amount of churn, resulting in multiple half-finished projects, rather than a single reasonably-decent UI.
For the last 10 years my Freerunner has been running on 'qtmoko', which is just Debian with the QtMobile UI (which AFAIK was a Trolltech demo).
These days there are even more FOSS mobile UIs floating around (Maemo, Meego, Plasma, Unity, FirefoxOS, Android, QtMobile, etc.) so hopefully Librem will just pick a stable OS (Debian?); pick one of these UIs, or interoperable components from a few; add on their Matrix messenger thingy, and ship.
Even if, for some reason, the flagship OS isn't polished enough on launch, there are other OS options that are. I'd argue that, from what I've seen, Ubuntu Touch is already good enough, and thanks to the UBports team it's still under development.
It's not the first attempt, either. Before them, there has been (in no particular order) firefox OS, ubuntu phone (Unity was initially meant as a "responsive" environment for mobile, laptop and desktop), QT mobile and maybe others. For a long time, opensource leaders wanted to build a "true" linux mobile OS, this is just a new step on that road, and I hope this will finally be a successful one.
I'm not sure why you consider it to be an impossible challenge, the hard part in building a new OS was building its kernel and coreutils, and this has been solved for about 30 years. Now, it needs to be adapted for mobile specificity.