Not all music notation software support quarter tone notation and playback. However, there are a few options for composers who wish to compose in this style.
Sibelius is one of the leading music notation software packages on the market. It has full support for quarter tone notation and playback. The software can be subscribed to for $19.92 a month, or can be purchased for $599. Sibelius is produced by Avid and can be found on its website.
Musescore is one of the leading free music notation software packages. It has partial support for quarter tone notation and partial support for quarter tone playback. It has enough support to enable a composer to notate, listen to, and print the music, but it is not as easy and quick as it is with Sibelius. The software can be found on its website.
By default, the program will not adjust the pitches of notes with quarter tone accidentals. To enable quarter tone playback, an external plugin is needed. Dixon has created a plugin that will enable MuseScore to do just that. To use MuseScore with quarter tone composition, follow the instructions on the MuseScore Instructions and Plugin Page.