[common] Towards the original author(s) or maintainer(s) of a project. Used in connection with software that is distributed both in its original source form and in derived, adapted versions through a distribution (like the Debian version of Linux or one of the BSD ports) that has component maintainers for each of their parts. When a component maintainer receives a bug report or patch, he may choose to retain the patch as a porting tweak to the distribution's derivative of the project, or to pass it upstream to the project's maintainer. The antonym downstream is rare.