Get Portable MKVToolnix Software Free. It is a program that allows you to create, inspect, and change Matroska documents in Windows, Unix, and Linux. Matroska is the new file format for multimedia. You can extract various data and tracks from these files and create mkvinfo (Matroska) files from other media files. The program doesn’t affect the system registry files as it is portable. You don’t need to install the program but can run it by copying it onto a flash drive or any other external device.