The Guitar Fretboard Explorer
The Guitar Fretboard Explorer shows the notes on a guitar neck for a variety of chords and scales. It should be useful to anyone learning to play guitar or as an reminder of the fingering of a seldom used scale. It supports a small variety of alternate tunings. It can show a quick comparison of two different items, for instance all of the notes in a major scale and only the notes in a major triad (chord).
It is also some very old code that needs to be freshened up. But it works fine as-is. Until a rewrite happens, please use the original at YourFriendPaul.com/Music/fretboard.php.
Some help on using the Fretboard Explorer can be found in the Guitar Fretboard Explorer's introduction and the Guitar Fretboard Explorer's controls articles.