MKVtoolnix is a set of tools to create, alter, split, join and inspect Matroska files(mkv). Command line tools but mkvmerge GUI included (mmg.exe). Use MKVExtractGUI/MKVE Wizard or MKVcleaver to extract/demultiplex mkv video and audio files.
MKVEXtractGUI and MKVE Wizard are demultiplexer GUIs that allow you to demux mkv streams, split video, audio and subtitle to separate files, from an MKV file. GUI for mkvtoolnix (mkvextract/ mkvmerge). Requires mkvtoolnix in same folder as mkvextractgui.exe/mkvewizard.exe.
MKVCleaver is a mkv batch extractor/demultiplexer. Batch extract data from MKV files. Requires mkvtoolnix. Put the MKVcleaver.exe file into a directory from where you want to run it. When it starts up, all the needed files will be extracted into the same directory.