SOFTWARE

PowerTabs
play, edit, print sheets and tablatures and make midis (freeware)

Chronotron
manipulate tempo and pitch separately when playing audio and video files (freeware)

Scale tool for Guitar
ScaleTool is a tool that visualizes scales and chords on fretboards (freeware)

Easy Chord for Guitar
EasyChord is a guitar chord dictionary - and maybe the worlds most simple one - for standard tuned six-string guitars. (freeware)

Band-in-a-box
programma di accompagnamento automatico intelligente per il tuo computer multimediale (commercial)

GuitarPro 5
play, edit, print sheets and tablatures and make midis (commercial)