I'm excited to share that my 7-year-old niece, who is showing a keen interest in web development, helped me code my personal website using HTML. She was responsible for the HTML structure, while I later implemented the styles and SEO tags. The concept for the site, including the use of watercolor images sourced from third-party sites, was all her idea!
I think it is from the Internet Explorer days. .ico is an actual icon file format on Windows and IIRC originally the icons were in that format, with support for GIF coming when Netscape supported the feature.
Works reliably (have never noticed an outage when interactively using or via my tooling that wraps around the API), product UX is stable, dev responds to customer support and feature enhancement requests, reasonably priced and good value (imho).