Acorn Draw files are the native format for vector graphics on RISC OS systems. The built-in Draw application can be used to load, edit and save files in this format. Thanks to software support from Acorn in the form of a system module for rendering Draw files and various tools and libraries written by third parties, the format was widely used. Although Draw files are used in a variety of applications, they are often used in conjunction with desktop publishing (DTP) and word processing software, and libraries of clip art would typically include drawings in this format.
Draw files contain a collection of objects, each of which is described by a type value, a length and a sequence of data. Groups and tagged objects also contain collections of objects that are nested inside their own definitions. Objects can be nested without limit. Object types include text, paths, sprites, text areas and font tables.
The file format was intended to be extensible: applications could be written to recognise custom object types, and new types could be registered with Acorn. Third party applications, such as DrawPlus, Vector and Poster, were created to provide enhanced editing and composition capabilities over the standard Draw application.
On RISC OS, Draw files have a file type of aff (DrawFile).