When does a feature become standard?

Our feature over in Reviews on how to put together an alternative to Adobe Systems' Creative Suite 3 has spurred IT executive manager putt1ck to ask: "When does a feature become essential? And an app a standard?"

Good questions to ask as companies move closer to considering open-source software as a true alternative to proprietary products. It also cuts to the heart of things for software makers, as they face up to the situation: How can they build their software so they will keep customers interested?

As putt1ck points out, 10 years ago artists got their jobs done without the software features they have now. So what aspect of the latest tools is the one they can't do without? Any software company who works that out in their own niche will have cracked the problem.