Mo File Stands For
Mo extension is associated with Machine Object File. You can open mo files with Gnu gettext software.
It is a file that consist objects which are referenced by any kind of software. If it is in this format, it can be installed by Gnu gettext software. Besides, you can edit mo files by importing. .mo files are like .po files, it means these are binary based files which can not be read and changed by the user easily.
To get detailed information, please check the following web page.
What needed for openin Mo file
Links stands for Mo file