What software is good for writing music ...?

The two leading software packages for writing music are Sibelius and Coda's Finale.

Sibelius Macintosh & Windows

• Sibelius Discussion List
• Scorch the Sibelius Viewer (free)

Coda Music Technology Macintosh & Windows

• Finale Discussion List
• Finale
• Finale Allegro
• Finale NotePad TM (free)
• PrintMusic!
• Finale MusicViewer the Finale Viewer
• Notation Software Feature Comparison: Comparison by Coda Music Technology of Finale, Allegro, and PrintMusic!

Members have also mentioned the following packages as good entry level notation packages, particularly for guitarists:

• TablEdit
• MusEdit
• Guitar Pro

For a comprehensive list of available software:

Acadia Early Music Resources List of Notation Packages

Kelly's Music and Computers