I’m not sure; the integrated GUI seems like a major differentiator for them.

Pi’s agent is supposed to be simple, and a simple ACP agent is like a couple hundred lines of code. Making a system that allows UI plugins is way harder.

Also not sure if you’ve seen but you can get ACP from Pi with https://github.com/svkozak/pi-acp It bridges Pi’s RPC mode to ACP, works okay but not amazingly. My thinking level selector in Zed has never worked with it but everything else I use has worked (I’m sure other things don’t but I must not use them).

Good points.

About what Pi/Earendil is going for, I can't really say but a while ago they created quite a stir in the Pi community for adding a trust system[0] which for many (me included) went against the loudly advertized "yolo" phylosophy, at that time I speculated it was a move to make it more palatable for the general population (whatever that actually means), so I'll stay optimist for ACP adoption for now.

[0]: https://pi.dev/docs/latest/security#understand-project-trust

The "general adoption agent" for Earendil is their other product Lefos, that is based on Pi and uses email as the interface.

FYI Pi can do RPC over stdio (though of course it's a bespoke thing, rather than standardised). I use Pi every day; never used the TUI (I forgot it even had one).