Skype and Zoom: Online software for hosting meetings, online tutorials, instructionals, etc
JamKazam: Using JamKazam, you can play music with other musicians from your homes across the Internet as if you were sitting in the same room. You can record your performances at the track level, share your recordings, and even broadcast your live sessions to family, friends, and fans.
Splice: Splice Studio allows producers to easily collaborate with friends around the world while also backing up their music projects using our free and unlimited storage.
Jammr:Install jammr on your computer to begin jamming. Public profile pages allow you to see and get in touch with others.
sofasession: sofasession lets you find other musicians and connect to them in realtime online to make music. Use sofasession to jam online, find friends and make music in realtime. sofasession makes your rehearsals and jams online. Tutorial here.
NINJAM: NINJAM is open source (GPL) software to allow people to make real music together via the Internet. Every participant can hear every other participant. Each user can also tweak their personal mix to his or her liking. NINJAM is cross-platform, with clients available for Mac OS X, Linux, and Windows.
ninbot: Ninbot is a server which allows musicians to play together, record, and broadcast live on the internet. Using a program called Ninjam, users are immersed in a high fidelity sychronized music session where they can interact and jam with other musicians in real time.