Patchwork is a web-based patch tracking system designed to facilitate the contribution and management of contributions to an open-source project.
Patches that have been sent to a mailing list are 'caught' by the system, and appear on a web page. Any comments posted that reference the patch are appended to the patch page too.
The project's maintainer can then scan through the list of patches, marking each with a certain state, such as Accepted, Rejected or Under Review. Old patches can be sent to the archive or deleted. A patch submitter can change the status of his patches for example when finding a bug or submitting a new version.