UltraStar Deluxe - A free and open source karaoke game inspired by the Singstar™ game, runs on Windows, Linux and macOS.
Sing! Karaoke by Smule - Karaoke with your favorite celebrity singers
KaraFun - KaraFun is the best online karaoke. Over 35,000 karaoke songs, with studio quality, at home or on the go. Regular updates. Free demo!
Singa - Singa is the best way to sing karaoke on mobile or tablet.
OpenKJ - Open source cross platform karaoke hosting software
SingPlay - SingPlay Karaoke Your MP3s developed and published by NexStreaming Corp.