| mdcs | MATLAB Distributed Computing Server Saved Session |
| mdd | MDict Resource Data |
| mdd | Notation Composer Midi Device Description |
| mdd | Quanquest SPSS Questionnaire Definition Data |
| mdd | Xilinx Microprocessor Driver Description |
| mde | ArchiCAD Education Module File |
| mdef | ANSYS Workbench Managed Data |
| mdex | Mifos Data Exchange XML Data |
| mdf | I-DEAS Master Drafting Machine Data |
| mdf | Insight II Molecular Data |
| mdf | Microsoft SQL Server Database |
| mdf | SDL Trados Studio Translation Memory Data |
| mdg | myPM Merge Data |
| mdif | EEsof Model MDIF File |
| mdinfo | iPhone Backup Information Data |
| mdist | PLINK Genomic Distance Proportion Matrix Data |
| mdk | Astra Schedule Schedule Data |
| mdl | Animation Master Model Data |
| mdl | Bentley MicroStation MDL Program |
| mdl | Cognos Exported Model Data |
| mdl | IBM Rational Rose Model Data |
| mdl | Leadwerks 3D Model |
| mdl | MapShots Model Data |
| mdl | MDL Molfile Data |
| mdl | Rapidform Model Data |
| mdl | STAR-CD v4 Model Data |
| mdl | Symbian OS MIME Type Library |
| mdl | Vensim Model |
| mdl0 | Nintendo Wii Model Data |
| mdm | BrainVoyager QX MDM Data |
