File extensions and how you open the files

From Linuxintro
File extension Contained format Program to open
*.7z See unpacKing files
*.djvu Deja vue files okular, djview4
*.exe Windows executable wine
*.mid midi files timidity
*.mkv matroshka kaffeine
*.ova virtual machine file vmware
*.ovf virtual machine file vmware
*.pdf portable document format acroread, okular
*.rpm rpm files for installing software rpm
*.vmdk vmware virtual disk vmware
*.vmx vmware virtual machine vmware
*.wav audio file format kaffeine