We strongly believe that the best proposal for you is the one you'll do. If you have any suggestions, come on IRC channel #musescore, or contact us on the developer mailing list. To officially apply your summer project idea, follow this link.
Also check ideas from previous years: http://musescore.org/en/developers-handbook/google-summer-code
Port a part of MuseScore to Native Client (NaCl). There are already some experiment with Qt and NaCl. It would mean the ability to display, play, transpose sheet music in the browser without any plugin.
MuseScore resources repository
MuseScore is highly customizable. Users can change soundfonts, add plugins, define workspaces, templates, palettes, languages etc... What if there would be an easy way to share all these resources in the cloud and a one click way to install/uninstall them in MuseScore.
Some resources to check OCS, Attica client library, KDE Bodega...
Jianpu notation support in MuseScore
Jianpu notation/Numbered musical notation is widely used in China. A large amount of Chinese music is recorded in Jianpu and most Chinese people are more familiar with Jianpu than standard staff scores. But there are relatively limited software for editing Jianpu and they have obvious disadvantages. In sum, there's a need for high quality Jianpu notation software. For more information: Here.
Improve MIDI import
MuseScore currently imports MIDI files quite badly. There are many areas in which MIDI import could be improved and most of them require smart algorithms. This project would target several key problems.
- Tuplet import: Currently, MuseScore considers only binary note values.
- Dot vs Tie: Currently, MuseScore always uses ties and never dots.
- Drums import
- Tempo changes
- Swing import: if a MIDI file is played with swing, MuseScore should be able to recognize it and notate it as straight notes, but still play swing.
- Voice separation: MuseScore puts everything under voice 1 currently.
- Treble/Bass clefs discrimination for piano: MuseScore currently uses a fixed point to separate the treble and bass clef. A smarter algorithm could be found.
Skills: C++/Qt, AI
Possible mentor: werner