1. Firefox: end-of-life browser built on legacy Firefox engine
2. Firefox Preview: work in progress, soon to replace the old Firefox, rebuilt from scratch on new engine
3. Firefox Focus: a minimal/reduced/simplified browser first developed to pilot the new engine
Klar is just the German name for Focus.
For example Firefox Lite: https://play.google.com/store/apps/details?id=org.mozilla.ro...
It appears to be an "Emerging Market Experiment" run by Mozilla Taiwan[0]
It also appears to be heavily based on or be a fork of Firefox Focus/Klar[1]
[0] https://github.com/mozilla-tw/FirefoxLite
[1] https://github.com/mozilla-tw/FirefoxLite/pull/2/files
1. Firefox: end-of-life browser built on legacy Firefox engine
2. Firefox Preview: work in progress, soon to replace the old Firefox, rebuilt from scratch on new engine
3. Firefox Focus: a minimal/reduced/simplified browser first developed to pilot the new engine
Klar is just the German name for Focus.