Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs.
π-Base, a community database of topological examples with automated deduction and powerful search.
Ohm is a library and domain-specific language for parsing and pattern matching. Like its older sibling OMeta, Ohm supports object-oriented grammar extension and allows pattern matching on structured data as well as strings.
GN is a meta-build system that generates NinjaBuild files, developed for Chromium. Standalone usage is possible, too.
Kernel bypass for networking. Good overview of available techniques.
Computer Science Courses that Don’t Exist, But Should
SABBAT, a twine. NSFW.