The DD file extension can be found as an image doodle for the C64 computers. These computers are 8-bit home computers that were released by Commodore International. In fact, the C in C64 means "Commodore" to identify the company. The DD file extension is the image doodle used only for this computer. Image doodles are unique in a sense, that these are created when the artist is unfocused on his drawing.
The DD file extension is associated with the Microsoft Visual Studio integrated development environment for Windows. The .dd file contains deployment diagram that is used to evaluate the deployment of an application system in a particular logical datacenter.
Files with the DD extension identify a compressed file archive created in Macintosh DiskDoubler Archive application. The DD format uses LZ78 compression algorithm, which compresses files immediately on the hard drive and expands them when opened in real time. DD files may be opened and edited with compatible software.