OCD file extension is used by OCAD, a tool for creating maps. Single OCD file stores map project created using OCAD tool. OCAD application offers many tools that allow users to create maps with various objects such as buildings, roads, wooded lands, etc.

OCD files can store many different types of maps (physical, tourist, city, etc.). Data in OCD format can be exported into more popular graphic formats or, for example, PDF files. OCAD is chiefly used in cartography, surveying offices, or universities.