1. It's actually largely based off the original terminal on Windows, conhost.exe. We were able to re-use a lot of the codebase for the core of the implementation, with a thin new UI layer. This means that enhancements to the terminal will also help enhance the inbox console.
2. I spent a LOT of time looking at using xterm.js, and eventually decided against it. The main factor was that although it would provide us a nearly complete VT implementation, it was critically tied to the JS ecosystem, and no matter how much time we spent engineering it, we'd still be coupled to having a webview render text. So we instead decided to write it in C++, which meant that we'd initially have less VT compatibility, but our perf would be better in the long run.
I just looked at the Terminus project page[0] and I'm really impressed that they seem to have run an entire linux emulator in the browser just to show off a terminal.
1. Is this based on Terminus or some previous OSS project?
2. Is this using xterm.js for the terminal emulation?