From Freedom Software Company:
Free MKV to AVI Converter is a simple, fun and easy way to convert video files. Users can quickly convert MKV to AVI and AVI to MKV. MKV files are a standard file type in the audio/video industry. They are an open standard container format file for digital multimedia. AVI or Audio Video Interleave is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. Using standard video players, MKV and AVI provide high quality playback and high compression rates to minimize disc space. Free MKV to AVI Converter is free, light and requires very minimal hard drive space.