MKVtools - MKVtools was primarily designed for processing mkv files for use in DivX enabled DVD players...
MKV Video Converter - Best MKV video converting software to download online videos from YouTube, Facebook, Twitter, etc.
MKVToolnix - MKVToolnix is a set of tools to create, alter and inspect Matroska files under Linux, other Unices...
MConverter - Online batch converter for most video, audio, image, e-book, document and archive file formats. Easy to use. No full-screen ads. Select files and folders from anywhere, including the clipboard (Ctrl+V). Save your files to any folder of your choosing.
Quinn - Your personal matchmaker
MKV/AVI to MP4 - mkv/avi to mp4 converts mkv and avi files in h264 video to mp4 files without reencode the video stream. Subtitle will be embed as soft subtitle. Convert speed is fast as video is not reconverted.