ABC FormatABC is a format for writing tunes in a portable and easy way. It was invented by Chris Walshaw, and is used for sending tunes via e-mail, for putting tune books on the net, and for typesetting tunes. There are now a number of different software packages available for handling ABC files on various platforms.
More information about the ABC format is available at The Official ABC Home Page. There you can also find other utilities, for printing sheet music from ABC files, etc.
For Windows systems, I recommend Abc2Win
for printing sheet music from ABC files.
I have typed in hundreds of tunes in ABC format, which are available on my ABC page.
There is also an ABC User Group Mailing List for those who are interested in discussing different aspects of abc notation.