WFC3 is being built by hundreds of scientific and technical personnel of NASA's Hubble Project. WFC3 is a true collaboration between sectors of government, industry, and academia. Most of the activities are centered at Goddard Space Flight Center (GSFC) in Maryland.
The team was selected in order to "reuse" as much expertise as possible as these institutions and companies have been closely involved with the development of the previous HST instruments. The main tasks of the WFC3 project are delegated to its partners (see table and charts). In addition to the partners, several contractors are employed to help bring WFC3 from concept to reality (see bottom table).
WFC3 is the first HST instrument to be developed as a "facility" instrument by the HST Project. The WFC3 developers perform their work as a service to the astronomical community. They do not get guaranteed scientific observation time on HST. This is a concept that has been used successfully by both the Planetary and Earth Sciences communities in their instrument development projects.