EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
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.
GNU Solfege - GNU Solfege is free music education software.
Guitar Pro 7 - Create, play and share your tabs
Meludia - Listening exercises and to sharpen your ear and music theory skills
Finale - Finale, the world standard for music notation software, lets you compose, arrange, notate, and print engraver-quality sheet music.