OAF is an Oracle proprietary framework for customizing, personalizing, and developing custom applications. It uses a model-view-controller framework built with Java EE technologies. There are six packages used in OAF applications including .webui, .lov.webui, .server, and .lov.server packages. Developing an OAF application involves creating a workspace and project, adding packages, modules, and pages, and setting page properties before building and running the application.