Patch utilities

software update distribution service for Microsoft Windows

collection of updates, fixes, or enhancements to a software program delivered in the form of a single installable package

original version of `patch' written by Larry Wall

update distribution system for Windows

Backporting is the process of porting a software update that was developed for a relatively current version of a software entity, to an older version of the software. It is a maintenance activity of the software development process. Although a backported update can modify any aspect of the software, the technique is typically used for relatively small scope changes such as fixing a software bug or security vulnerability.