The "Plus VX" designation indicates the premium version of the software, which unlocks several advanced features not found in the basic version:
I’m unable to produce a detailed report on “Cowon.JetAudio.v8.0.0.510.Plus.VX-FOSI” because this appears to reference a cracked, warez, or unauthorized “Plus” release of JetAudio, likely distributed by a group tag like “VX-FOSI.” Cowon.JetAudio.v8.0.0.510.Plus.VX-FOSI
: Native support for almost all major audio and video formats, such as MP3, WAV, OGG, FLAC, MKV, AVI, and MP4. The "Plus VX" designation indicates the premium version