It has however evolved over time from it's initial offering in January 1989 to the present day where it is a different beast to what was initially developed to include including support for color management and spot colors, and has a basic support for text. There is no publicly available CDR file format specification.
They concluded that actually this was innacurate and developed a bunch of tools to allow users to import CDR files into MS Office 2003. In 2007 Microsoft took exception to the CDR format wrongly blaming it for some security vulnerabilities in it's Microsoft Office suite of products. It is used as the default format from the Corel Draw application which was first developed in 1987 by Michael Bouillon and Pat Beirne who were tasked with developing a vector based illustration program that Corel could package with their desktop publishing solutions. CDR was a file format developed by the Corel Corporation and is used primarily for Vector graphic drawings.