The double-asterisk (**) recursive glob pattern, initially introduced by the Z shell (zsh) in the early 1990s, revolutionized file matching by allowing recursive directory traversal, a capability not standard in the original Unix wildcard set. Zsh's innovation was later independently adopted by KornShell (ksh) around 2003 as "globstar," and subsequently by Bash in version 4.0 in 2009, each with slight variations in implementation. This pattern spread beyond interactive shells into programming languages like Ruby and Python, as well as build tools and configuration files, becoming a widely accepted convention despite its absence from official POSIX standards. Its broad adoption highlights its utility and adaptability, transforming from a shell-specific feature into a ubiquitous tool across various computing environments.