1. A method of operating a computer system comprising: identifying mashup application performance monitors that are applicable to a mashup application that is being created in a mashup application development environment; and instructing the mashup application development environment to embed selected ones of the mashup application performance monitors into the mashup application that is being created in the mashup application development environment, responsive to a selection of the selected ones of the mashup application performance monitors from the mashup application performance monitors that are applicable to the mashup application that is being created in the mashup application development environment.