August 2018 will see a new release of the Scratch programming environment. Scratch 3.0 preview needs WebGL installed. I got scratch 3 working by installing chromium browser on my Linuxmint desktop.. This seems to have WebGL support built in, the default Firefox browser does not appear to have this. (I may be wrong, YMMV)
sudo apt install chromium-browser
Scratch 3.0 builds on 2.0 and adds new features including plugins micro:bit, Lego WeDO 2.0, Mindstorms EV2 support. Looks really nice.
I am guessing there will be support for Raspberry Pi at some point but for the Raspberry Pi scratch build.
You can have a go with the preview of 3.0 at
Have fun !