One redditor asked about it on the most recent AMA:
Hi, is there a plan to release protondrive for linux?
Proton CEO’s answer:
We’re currently looking at options for how to fund this. It’s an expensive development because Linux has so many different flavors and we need deep integration with the filesystem, and it is not yet clear if there are enough Linux users that would allow us to offset the cost of this development. Like many things Linux, it may eventually just have to subsidized from Proton’s reserve budget. That doesn’t mean it won’t get done, it will just take longer since we are also subsidizing several other efforts at this time, such as the Proton VPN free servers for elections campaign: https://protonvpn.com/blog/free-servers-before-elections
-Andy
Source: https://www.reddit.com/r/ProtonMail/comments/1ff211y/comment/lmrdepr
@abobla
I kinda struggle to believe it’s that difficult. I mean, Tresorit has a pretty good and functional Linux client. What have they done which makes it sustainable for them?
Filen.io also has a pure sync-client, which is distributed as an AppImage. This also works, but the FUSE integration Tresorit provides is quite awesome and performing quite decently.
I would actually recommend Proton to start the development on an older Linux distro. Like RHEL/Alma/Rocky 9 or Debian 11 (which is EOL, though) and make it run there. Moving from that distro to newer distros will then go smother and you’ll get other distros supported quicker.
The mistake too many Linux efforts does is to take the “latest and greatest” distro version - often coupled with what a single Linux developer considers the “most used distro” and then hits lots of challenging when needing to support older distros. That’s going to be painful.
@protonprivacy Please take note and forward to Andy and other managers.
Synology also has a functional Linux client.