MuseScore teaser
MuseScore is a free cross-platform WYSIWYG music notation program that offers a cost-effective alternative to commercial programs such as Sibelius, Finale and Capella.
You can print beautifully engraved sheet music or save it as PDF or MIDI file.
Some highlights: 
- WYSIWYG, notes are entered on a "virtual note sheet"
- Unlimited...