1. A method for generating user-accessible effects, comprising: receiving a library of operators, each operator including a set of operations performable on an image; interacting with a designer via a node-based graphical user interface to receive an effect definition, wherein the effect definition defines a set of operators to be executed on an image and a set of parameters associated with each operator; responsive to a change of the effect definition, previewing a result of the effect definition applied to a developer-specified image; saving the effect definition to an accessible memory; and uploading the effect definition to a server for compilation into a script module for execution responsive to a user request.