and various synchronization primitives like mutexes, semaphores, and conditions, Unicode string support, locale and internationalization support including localizing string resources, comprehensive resource support, and basic XML parsing. Graphics features include anti-aliased graphics using the Anti-Grain Graphics Library, full affine transformation support, images with direct access to the image's pixel bits. Additional application support features also include undo/redo classes, advanced support for Model View Controller. As a general rule, the framework makes as much use as possible of the Standard Template Library, avoiding duplication of work on things like container classes, or string handling. Where possible the framework builds on top of the native C++ RTTI support such as using dynamic_cast and typeid, as opposed to simply re-implementing it. Most OS objects, such as files, threads, graphics devices, and window controls (or widgets), and so on, are implemented using a thin layer that talks directly to the specific native object. UI controls are not emulated for the most part, instead the framework uses native widgets in most places. Direct access to the underlying OS "handle" is allowed in cases where platform specific functionality is needed, allowing the developer to easily call the platform's native APIs. See also Software component Widget toolkit List of widget toolkits Qt wxWidgets Motif GTK+ Gtkmm FLTK FOX toolkit Ultimate++ External links The VCF Reference Documentation The VCF Source Documentation The VCF Builder homepage Anti-Grain Graphics Library Software using the BSD license Widget toolkits