I'm new to it too, I've known about its existence but have been thinking about adding support for it to a project I'm starting soon - really to learn more about it (I tend to learn best by doing!)

It's goal is for each of us to have personal ownership of all our data online, and full control over who can access what. That's certainly something I can get behind! You do this by creating a "pod", which is essentially a database of all your data (I think organised into groups, e.g. each organisation can have their own group of data), which you can self-host if you like, along with the ability to control access.

It's current impact I would say is near zero. But TBL is a person with a reasonable amount of pull, and he's setup his own company providing commercial services (presumably, consulting). My guess is they're dealing with governments and mega-corps - there seems to be very little effort pushing it to "the masses" (i.e. application developers).

The theory sounds interesting but the practicalities of it seem to offer a lot of challenges, so I think the best way to get a real sense of whether it has legs or not is to build something!