Lifecycle
When referring to a software program, the lifecycle is the guaranteed time a company will support and improve a program. For example, the expected mainstream support lifecycle of Microsoft Windows 7 is until January 13, 2015. When that date is approaching, if Microsoft feels that it is necessary to extended that lifecycle they may extend certain portions of the lifecycle as they did with Windows XP because of the number of people still using it.
Also see: Discontinue, Software