What are the best applications available for writing sheet music?
If you're looking for a free program, Musescore is ideal. However, the capacities of Musescore are limited, and if you're looking for more, you may want to take a look at Sibelius or Finale. Sibelius is more streamlined and user-friendly than Finale, but there are a few things that Finale can do which Sibelius finds very difficult or impossible. Which program is best depends on what you are looking to do with it.