This paper presents an approach to software construction that relies on the connection of reusable components. The approach is derived from the observation that a design framework plays a central role in the reuse process in the sense that both the design of applications and the design of reusable components must follow the same design discipline. The interaction between components is mediated by an object: the gluon. Gluons are attached to reusable components and they represent the rights to a service provided by the component. Gluons can be seen as coupons: once detached they grant a service that can be exchanged among objects. Gluons can also encapsulate an activity performed by a set of cooperating components. With this approach, the construction of applications can be seen as a market where components that ask for services can purchase rights from other components that offer them .