Principles that put the "Extreme" in ExtremeProgramming.

	* ExtremeProactivity
	* ExtremeFrequency

These are applied to ExtremeValues to effect ContinuousCommunication and ContinuousSimplicity, which together achieve the goal of XP to EmbraceChangeContinuously.

The number of software development patterns or strategies and principles of the form "do <<thing>> early and often" abounds throughout the literature and the web. The <<thing>> is often one of: integration, build, test, release (for open source ;-) and the "early and often" part is what makes the thing an important part of an overall IterativeAndIncrementalDevelopment solution.

You can think of "proactivity" as the "early" part, and "frequency" as the "often." The way XP differs from what might be considered more traditional IterativeAndIncrementalDevelopment methodologies is that it does things
''extremely'' early and 
''extremely'' often.
Hence ExtremeProactivity and ExtremeFrequency.