Developers build all the current software periodically


For iterative development to work well, it is necessary to make sure that components work together.   Provide a mechanism to allow developers to build all the current software periodically.


Incremental Integration


EarlyAndRegularDelivery necessitates integration of all components prior to delivery.  However, when practicing IterativeDevelopment without regular delivery, it is still strongly recommended to integrate the components and ensure they work well together.  Integration provides feedback that the components work together, and discovers problems in cases where they do not.  Development in subsequent iterations proceeds with the benefit of having received this feedback.  This enables some problems to be avoided where the same mistakes could have been repeated.  It is of use to allow developers to build, at their choice, against the latest software or against any earlier NamedStableBases.