| File Extension | Description |
|---|---|
| .bin | optiSLang classic postprocessing file |
| .ini | optiSLang configuration file |
| .omdb | optiSLang monitoring data base |
| .opd | optiSLang project directory |
| .opf | optiSLang project file |
| .opf_autosave | Automatically saved project file |
| .otpl | optiSLang templates file |
| .orv | optiSLang raw values file |
| .pro | optiSLang 3 problem definition file |
| .pye | Encrypted Python source file |
| .log | optiSLang log file |
| .inuse | Internal file used to track whether projects are currently open |