MyGuitarTuner.com - Online microphone tuner for guitar, ukulele, violin and other instruments. Tune by ear or using the microphone of your device. It's fast and accurate algorithm makes it one of the best online microphone tuners available.
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
Metronomus - Powerful and beautiful online metronome
MuseScore.org - Create, play back and print beautiful sheet music with free and easy to use music notation software MuseScore. For Windows, Mac and Linux.
LINGOT - Musical instrument tuner, LINGOT is a musical instrument tuner.
Finale - Finale, the world standard for music notation software, lets you compose, arrange, notate, and print engraver-quality sheet music.