Crystal Clear (software development)
Crystal Clear can be applied to teams of up to 6 or 8 co-located developers working on systems that are not life-critical. The Crystal family of methodologies focus on efficiency and habitability as components of project safety. Crystal Clear focuses on people, not processes or artifacts.
Crystal Clear requires the following properties:
- Frequent delivery of usable code to users
- Reflective improvement
- Osmotic communication preferably by being co-located
Crystal Clear additionally includes these optional properties:
- Personal safety
- Easy access to expert users
- Automated tests, configuration management, and frequent integration
Further reading 
- Crystal Clear, A Human-Powered Methodology for Small Teams, Alistair Cockburn, October 2004, pages 336, paperback, Addison-Wesley Professional, ISBN 0-201-69947-8.
- Alistair Cockburn's introduction to the Crystal family of methodologies
- A quick overview with links to sample chapters from the book