I was also going to suggest Haiku. It’s the spiritual successor to BeOs. I was always disappointed that didn’t become more popular.

Isn’t this basically how lisp works?

I use Emacs’ Org Mode. It may not be exactly what you’re looking for, but it is highly versatile.

He did say he was doing it to learn. Maybe when he’s done he will be able to appreciate what goes into making a viable browser.

Ditching TCP/IP and defining a whole new protocol stack would require your ISP to have routers that know how to route this new protocol without IP addresses. Also, every router between the source and destination would have to support the protocol also. That seems like a huge hurdle. We can’t even get mainstream ISPs to support IPv6 in the last 25 years.

Unless the author intends to layer this on top of IP, which defeats the defined goal.

If you did this, you would be running your own “Internet” with only your own routers connecting to each other.