From reddit announcement:

Hi everyone, This is Andy, Proton founder/CEO here. I just wanted to share the news that Standard Notes and Proton are joining forces.

This was an idea that people from both the Proton and Standard Notes communities have brought up repeatedly over the years, and after discussing it with Mo, the founder of Standard Notes, we both felt it was a good idea.

Both Proton and Standard Notes have unique shared values. We are both community-driven, not VC-financed, and committed to open-source. By joining forces, we hope to deliver more valuable services to both the Proton and Standard Notes user communities. A bit more about this on the Proton blog here.

As always, thanks for your support as we continue to fight for a more private internet, now with even more people on the team!