Meludia - Listening exercises and to sharpen your ear and music theory skills
Sibelius - Sibelius is a virtual score creation tool which allows composers to easily create new piano scores, developed by Avid.
GNU Solfege - GNU Solfege is free music education software.
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.
Auricula - Practice your sense of hearing and learn to identify intervals for your musical development.
Finale - Finale, the world standard for music notation software, lets you compose, arrange, notate, and print engraver-quality sheet music.