This format is used for data exchange in programs that work with vector graphics from Corel, and also for printing completed designs. It contains image data and also the metadata that describes it. In CMX it’s possible to store layers that can be independently edited. The format is recognized by Adobe Illustrator versions 6-8.
docm : Microsoft Office Open XML with Macros Enabled
The M of DOCM stands for macro. Macros are programs embedded in Office documents used to automate different tasks. Staring from Word 2007, DOCX documents that contain macros are saved with the DOCM extension.