Bumble is actually just another name for BYOB. I’m just calling it Bumble as a fun way of shortening B(YOB for C)rumble 🙂
Jens Moenig (with help from Brian Harvey) developed BYOB from Scratch to add more advanced computer science programming concepts and features so that it could be used up to university degree level.
When Scratch2 was developed – it used a lot of the ideas in BYOB.
I’ve used BYOB instead of Scratch purely because it lets me easily make your custom blocks to talk to the Crumble.