Mhm, this is a proprietary OS developed by a dilapidated company… Here is another OS sharing the Nokia/MeeGo heritage, except fully open source and actively developed (not ready for general use either, AFAICT [yet]): https://nemomobile.net/

Comparing Jolla to Nemo with the argument 'actively developed' is a huge stretch.

Nemo is a great project, but only build by one guy (neochapay) in his spare time.

Jolla still has ~5 full-time engineers and a super active community.