The ability to compose software from high level components is as sought after as it is elusive. The REST architectural style used in the World Wide Web enables such plug-compatible components in distributed settings.

We propose storage combinators, a type of plug-compatible component that can be used as generic intermediary in a non-distributed setting.

Storage combinators combine several stores – components that support REST-style verbs – into a single component that also provides a store interface.

This mechanism allows a few basic components to be combined in many different ways to achieve different effects with or without adaptation. It correlates with reported increases in productivity while performing well in commercial applications with millions of users.