There's some surprising stuff in this codebase. For example, https://github.com/xai-org/grok-build/blob/b189869b7755d2b48... is a "self-contained terminal renderer for Mermaid diagrams", which renders a subset of Mermaid chart types using Unicode box-drawing.
I had Fable 5 compile that Rust code to WebAssembly and build a browser-based playground for it, so you can try it out with Mermaid diagrams here: https://tools.simonwillison.net/grok-mermaid
A few more notes on my Grok code explorations on my blog: https://simonwillison.net/2026/Jul/15/grok-build/