notation

Online music score editor enabling real-time collaboration and editing in your web browser, supporting MusicXML, MIDI, PDF, MP3, WAV, percussion notation, history tracking, Google Hangouts video, metronome tools, and cross-device access for composers and students.

Guitar Pro enables editing tablatures for guitar, bass, and more, with support for piano and drums. It features a realistic audio engine, interactive practice tools, and access to thousands of online tabs, facilitating music composition and transcription.

Compose, arrange, and share music using free, open-source software for Windows, Mac, and Linux with integrated playback, fast note entry, MIDI, MusicXML, PDF support, multilingual UI, and direct connection to an online sheet music community for sharing scores.

NoteWorthy Composer is a graphical score editor intended for the creation of sheet music, but it can also import and export MIDI and Karaoke files and can export graphical WMFs. The user interface works either from the keyboard or the mouse.

Rosegarden is a well-rounded audio and MIDI sequencer, score editor, and general-purpose music composition and editing environment.

Complete music notation and composition app for iPad.