M2k
From Just Solve the File Format Problem
M2k file format is the file format for the qualitative data analysis software from MAXQDA.
Format
There is not much information about the file format, but it is a MS Access compatible format. If you open the file in a hex editor you see "Standard Jet DB". You can also rename the .m2k file to .mdb then you can open it in MS Access. There is also a free reader application that can export the data in different formats, for example XML.