Arobas Music Guitar Pro is a multitrack editor of stringed instruments (especially fretboarded, like guitar and bass) tablature and musical scores, possessing a built-in MIDI-editor, a plotter of chords, a player, a metronome and other tools for guitarists and musicians. It has versions for Windows, Mac OS X (Intel processors only), Linux, iOS (iPhone, iPad), Android and BlackBerry. Guitar Pro from version 5.0 outputs sound by means of a library Realistic Sound Engine (RSE) which uses high quality recorded samples of guitars, basses, drums and from version 6.0 higher range of instruments for more realistic playback. Files composed using Guitar Pro are stored in the GPX, GP5, GP4 and GP3 format, corresponding to version 6.x, 5.x, 4.x, and 3.0 of the software. Guitar Pro from versions 1.x to 2.x used GTP format. Soundbanks are stored in GPBANK (6.x) and FSB (5.x) formats. Guitar Pro from version 6.0 supports also templates stored in files with GPT extension - technically this is GPX format.