Nero Multimedia Suite still supports MMV format and with that you should be able to export the video to common AVI format.
Convert MicroMV movie to Audio Video Interleave movie.
We have found 2 software records in our database eligible for .mmv to .avi file format conversion.
Microsoft Windows software - convert mmv to avi on Windows
Nero Recode is software tool for Microsoft Windows operating system, which allows users to import, rip, convert and edit digital audio and digital video files.
Convert from mmv file
to avi file
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned mmv to avi. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert mmv to avi on OS X
MPEG Streamclip for Mac is a high-quality video converter, player, editor for MPEG, QuickTime, transport streams etc. MPEG Streamclip supports MPEG, VOB, PS, M2P, MOD,VRO, DAT, MOV, DV, AVI, MP4, TS, M2T, MMV, REC, VID, AUD, AVR, VDR, PVR, TP0, M2V, M1V, MPV, AIFF, M1A, MP2, MPA, AC3 and other video file formats.