EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
GNU Solfege - GNU Solfege is free music education software.
Meludia - Listening exercises and to sharpen your ear and music theory skills
KDE Minuet - Free music education software, thoughtfully designed to push your musical skills to the next level.
Perfect Ear - A simple yet advanced application for improving your solfege skills.
Auricula - Practice your sense of hearing and learn to identify intervals for your musical development.