I'm posting to "Discussion" to see what the community stance is, as it's manifest that Billy is no longer under active development: the last version was released back in 2008.
My personal highlights would go to gapless playback as well as for online stream recording -- which I haven't tested in any way. What I did test is opening a very large music folder with many sub-folders and, at first, it seemed that Billy had choked; I waited it out and it finally pulled through without any errors.
Billy is an audio player that allows you to quickly play an entire directory of MP3 files. It can usually load files 2 to 8 times faster than winamp or media player. Billy plays music albums without any gaps between tracks, so an overlapping applause or beat will continue. The player is 100% controllable by keyboard and its easy finder and special rename functions help you to find and organize your files quickly.
Billy's last release (Beta v1.04k) can't be downloaded from the homepage -- it is displaying a "Download temp. offline" notice -- but can be had from https://codecpack.co/download/Billy.html, among other places.