Although this isn't a direct answer to your question, but everything that can be done in Herdr is trivially discoverable by asking a CC (or equivalent) session inside Herdr. In fact a lot of the things I do in Herdr I do by asking an agent to do it for me, instead of trying to learn how to do it manually.

Some things might require a non-trivial workaround, but a coding agent will also happily build and test it for you.

It is using JavaScript for user interface customization via:

https://gpui-kit.com/shell/

That's funny, I got tired of tmux the other day (it got into 100% spin loop from an unsigned int underflow used as a loop condition variable. and I debugged it all by myself like a big boy, without LLMs!) and built something that seems to be identical in architecture in terms of the "supervisor which allocates pty, just stream bytes, client decodes" part. I even use libghostty for the HW accelerated GUI I built. It's the right way to go imo and it's not too difficult to build... hence...

I don't really understand why they would turn this into a company. I become suspicious of products that raise a lot of VC money, implying that they expect a unicorn-ish valuation, where I don't see them being able to justify their valuation via obvious monetization techniques (e.g. selling a classic license for a GUI app where you get updates for some period of time, usually a year, and then you get to keep the software, but no longer get updates, just in case people forgot how things worked before subscriptions).

That usually implies something like selling cloud subscriptions, vendor lock-in, or selling data. I'm happy to be wrong, but it's just an extremely common pattern. And as an aside, I know there's an impulse to monetize everything, but I think we should probably fight that impulse.

Got my invite today. My jaw dropped.