1 project is written in Zig, listed alphabetically. It is Makko. All of them site and docs generators, most of them open source. 38 records do not record this field, and cannot appear here either way. Counts only projects with momentum; the full list has the rest.
What is the best web software written in Zig?
We don't know. A portfolio, a shop and a documentation site need different things from their software, and so does a team of one against an agency. Nobody pays to be listed here and the order is alphabetical.