Music notation programs on the computer have been around for a long time. Finale and Sibelius are two standards in the music industry. As times (and technology) have changed there are some new players in the field and one seems pretty exciting.
Enter Noteflight. Noteflight® is an online music writing application that lets you create, view, print and hear music notation without having to even download a program. It works in your web browser and it's easy enough for younger budding composers. Work on a score from any computer on the Internet or share with other users or your teacher. Like many "webware" sites, it offers a free version or a premium account which adds additional features. I highly recommend adults and child students try out at least the free version and start making your own music.
Terry Smith teaches piano and voice privately in the Phoenix, AZ area and online anywhere using an innovative approach called "PLAY NOW!"