1. A system comprising: an electronic catalog storing at least: a plurality of service images capable of being executed in virtual computing devices within a hosted computing environment to implement functionalities on behalf of customers of the hosted computing environment, wherein each service image comprises at least one software application, a uniform control object, a first instruction set associated with the uniform control object and with a first service image of the plurality of service images, the first instruction set designated by a provider of the first service image to control virtual computing devices executing the first service image on behalf of individual customers of the first service image, wherein the first instruction set, when executed, causes a computing resource within the hosted computing environment to implement an operation, with respect to the virtual computer devices executing the first service image, by undertaking a first set of actions associated with the first service image, and a second instruction set associated with the uniform control object and with a second service image of the plurality of service images, the second instruction set designated by a provider of the second service image to control virtual computing devices executing the second service image on behalf of individual customers of the second service image, wherein the second instruction set, when executed, causes the computing resource to implement the operation, with respect to the virtual computer devices executing the second service image, by undertaking a second set of actions, different from the first set of actions, associated with the second service image; and a marketplace computing device comprising a processor and in communication with the electronic catalog, the marketplace computing device configured to: generate a first user interface, including the uniform control object, for presentation on a computing device associated with a first customer; determine a first virtual computing device on the hosted computing environment that is executing the first service image on behalf of the first customer, wherein the first virtual computing device implements functionality corresponding to the first service image; following an interaction of the first customer with the uniform control object of the first user interface, request the computing resource to execute the first instruction set, designated by the provider of the first service image, to perform the operation on the first virtual computing device executing the first service image on behalf of the first customer; generate a second user interface, including the uniform control object, for presentation on a computing device associated with a second customer; determine a second virtual computing device on the hosted computing environment that is executing the second service image on behalf of the second customer, wherein the second virtual computing device implements functionality corresponding to the second service image and is distinct from the first virtual computing device; following an interaction of the second customer with the uniform control object of the second user interface, request the computing resource to execute the second instruction set, designated by the provider of the second service image, to perform the operation on the second virtual computing device that is executing the second service image on behalf of the second customer.