Justine Alexandra Roberts Tunney (born 1984) is an American software developer and a former activist for Occupy Wall Street.

[2][a] In July 2011, Tunney registered the @occupywallst Twitter handle and occupywallst.org domain, which became the main online hub for the Occupy movement.

[7] In 2016, Tunney discovered that open-source software projects on GitHub depended on an Apache Commons library with a security vulnerability.

Tunney wrote a C library and web server named Redbean 2 that runs on multiple platforms as a single binary.

On October 31, 2023 Tunney released the third edition of Cosmopolitan, the libc implementation used to make Redbean, which compiles a single binary that runs on multiple operating systems.