EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Audioalter - Your online audio toolkit. A collection of easy-to-use web tools for all your audio files
GNU Solfege - GNU Solfege is free music education software.
Transcribe - An online app that reduces the pain of converting audio & video to text. Saves thousands of hours every month for journalists, lawyers, students and professional transcriptionists all over the world, including researchers in Antarctica.
Meludia - Listening exercises and to sharpen your ear and music theory skills
Tune Transcriber - Learn and transcribe music for free from your web browser (no install needed).