GNATS is a portable incident/bug report/help request-tracking system which runs on UNIX-like operating systems. It easily handles thousands of problem reports, has been in wide use since the early 90s, and can do most of its operations over e-mail. Several front end interfaces exist, including command line, emacs, and Tcl/Tk interfaces.

GNATS is a set of tools for tracking bugs reported by users to a central site. It allows problem report management and communication with users via various means. GNATS stores all the information about problem reports in its databases and provides tools for querying, editing, and maintenance of the databases.

GNATS is the GNU project's bug-tracking software.