See https://github.com/tomjridge. Some repositories of interest (in roughly chronological order):
Ott: "Ott is a tool for writing definitions of programming languages and calculi."
Lem: "Lem is a lightweight tool for writing, managing, and publishing large scale semantic definitions."
SibylFS, a test oracle for file systems.
tjr_btree, a CoW B-tree library in OCaml.
Some of these use travis, see here for build statuses.
See the separate page parsing
See the blog article