The speed in development in Mykosmos/BOS comes from two directions. The first is the type of development cycle and the second the easy of programming business procedures (few lines of code for a big result). Now for the first direction, the development cycle:
There is no "design-compile-linking-running" in the development cycle in Mykosmos/BOS. The programmer enters the application (as a user) and by right-clicking the mouse "designs-scripts-tests" every resource (form, report, menu, scripts, database, and agents). The application is always in running mode except that the programmer can select any resource and "create-redesign" it. This can happen even on the customer's site for a delivered application (test-develop using live data).
When we code business procedures the Mykosmos/BOS is unbeatable (not to mention that other RADs simply cannot program business procedures at all!). See in Customer Service Automation how a business procedure becomes a coordinator agent.