1. A popup control development subsystem, including: a hardware processor connected to memory; a code generator running on the processor that generates code which when executed interacts with a controller-and-view interface and that implements menu, auto complete, date picker, and dialog popup controls, the generated code including: a popup control implemented by a base popup container that contains at least a trigger component and a target component that interact with the controller-and-view interface to respond to transition events, wherein the transition events cause the popup control to collapse, expand, show and hide the popup control, and to recognize a trigger-select; generation of the trigger component by the code generator includes generation of markup that causes a browser to use supplemental accessibility information in the markup to enable people with a visual impairment to perceive web content, wherein the supplemental accessibility information includes a text alternative for non-text content; the trigger component, when invoked, causes the controller-and-view interface to invoke the target component; and the target component, when invoked, reveals and enumerates selectable target actions; and a code editor that interacts with a user to: accept a user selection among the menu, auto complete, date picker, and dialog popup controls and invokes the code generator to generate code for the base popup container, which contains code that extends base popup code to implement the selected popup control, including code that implements the trigger component and the target component corresponding to the user selection; accept user inputs to complete the base popup container, the trigger component and the target component and implement a completed popup control corresponding to the user selection; and store the completed popup control for later use.