The MLT file format is an XML-based project file used primarily by the open-source video editor Shotcut. It does not contain actual video, audio, or image data; instead, it acts as a container for a set of instructions that describe how a video project is constructed. This includes references to the file paths of source media, the sequence of clips on the timeline, applied filters, transitions, color grading settings, and keyframe data. Because it is a text-based XML file, it is lightweight and allows users to save their editing progress without duplicating large media files. When a user opens an MLT file, Shotcut reads the XML structure to reconstruct the editing environment, allowing the user to continue working exactly where they left off. It is essentially a map that tells the software how to render the final output based on the original source assets.