PiyoPiyo is a music format made by game developer
Daisuke "Pixel" Amaya, used in his game
Ikachan. It was also planned to be used in Cave Story, before the Organya format was developed and used for that instead. Pixel's PiyoPiyo editor software is a bit difficult to use, especially with newer operating systems. Hence, an in-browser version of this software has been developed. Have fun making PiyoPiyo music!
PiyoPiyo Editor (Browser version)
You can listen to some of Pixel's
sample music, that was bundled with his editor, by choosing a song from the drop-down list. You can also play .pmd files from external sources by inputting the direct URL, if so desired. Unfortunately for some reason most sites won't work, the only file upload site I've found that works for this is
File Garden. And you can upload your own .pmd files from your computer. You can edit and save your music, and export it to MIDI as well.
This browser port of PiyoPiyo is basically a slightly repainted version of
Organya-JS, courtesy of
Alula.