9. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising: for entries that have been declared in a form and that identify available connections to data repositories and fields of the form that are associated with the connections, enabling a one-to-many mapping from fields in the form to one or more data repositories using declarative statements that specify a task to be performed, but not how the task is to be performed; inspecting the entries to identify a field from among the fields of the form associated with first and second connections from among available connections identified by the entries; importing first data from the first connection; associating the imported first data with the field from among the fields of the form; exporting the first data associated with the field from among the fields of the form to the second connection; importing second data, different from the first data associated with the field from among the fields of the form, from the second connection; disassociating the first data from the field from among the fields of the form; and associating the imported second data with the field from among the fields of the form.
9. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising: for entries that have been declared in a form and that identify available connections to data repositories and fields of the form that are associated with the connections, enabling a one-to-many mapping from fields in the form to one or more data repositories using declarative statements that specify a task to be performed, but not how the task is to be performed; inspecting the entries to identify a field from among the fields of the form associated with first and second connections from among available connections identified by the entries; importing first data from the first connection; associating the imported first data with the field from among the fields of the form; exporting the first data associated with the field from among the fields of the form to the second connection; importing second data, different from the first data associated with the field from among the fields of the form, from the second connection; disassociating the first data from the field from among the fields of the form; and associating the imported second data with the field from among the fields of the form. 14. The non-transitory computer storage medium of claim 9 , wherein the first connection provides input to a first data repository and the second connection receives output from a second data repository.