Multi Commander is built around a large Extension/Plug-in architecture.
An SDK is available so that other developers can create extensions and plug-ins for Multi Commander.
These extensions can create GUI items in tabs in Multi Commander and interact with the Core and add Menu Items, ToolBars and define Custom Commands.
Examples of Application Extensions in Multi Commander are MultiFileViewer (the default file viewer), Search, MultiTools (that contains the tool ChkSum that can Create and verify MD5/SFV checksums).
All filesystem support is done via plug-ins, but the filesystem need not include only files and folders. It can include the FS-Registry plug-in, that lets you browse and modify the Windows Registry as if it were a filesystem.
File Operations Plug-ins
These plug-ins can be used when performing copy and move operations. There are three ways for these plug-ins to hook into file operations:
When the queue is being built, eg. for changing name or target location
during data transfer before data is written if a plug-in needs to modify data, eg. encrypt it
after the entire file has been copied or moved: for example, adding metadata to a file, extracting metadata from a file and adding it to a database.
This plug-in will extract property information from files that can be used for extended columns in an Explorer panel.
For example, FS-Registry contains a FileProperties plug-in that adds the 'Data' column when browsing the Windows Registry from within Multi Commander.
For pictures you can add columns to view picture exif or image information like height, width, date created, GPS coordinates, etc.