The file extension CGZ identifies files in Web Computer Graphics Metafile format that have been additionally compressed. WebCGM is a free and open international standard for storing 2D vector graphics, raster images, hyperlinks and effects. The standard is based on the CGM standard and contains both limitations and extensions to CGM. Grouping of elements as well as layers are supported.
The format was developed for use on the Web and is also recommended as standard by the W3C. It is currently not supported strongly.