7z is a compressed archive format using 7-Zip architecture. The VGMPF uses 7z compression for certain file collections because of its high compression ratio which is usually better than ZIP, RAR, and ACE formats, but more importantly, because it is open source and patent free.
Some audio files use the LHA compression and structure of this file to reduce their size. Multiple VGM files can be 7-zipped into a single VGM7Z archive, some formats like MDZ and YM are already LHA archives.
To decompress a 7z file, download the latest 7-Zip program. 7-Zip not only supports older archiving formats like ZIP, RAR, and ACE, but it also compresses better than their native applications. Since the December 2008, the 7z format is in the public domain.
Reason For Inclusion
Some audio rip archives in the VGMPF use the 7z format because it compresses much better than ZIP and patent free.