VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Ring4 Meeting - Dead simple video conferencing - free, in browser
MPV - MPV is an audio and movie player based on MPlayer and mplayer2.
Stork.ai - AI-Based Collaboration for Hybrid Teams. Rich media messaging, advanced video and voice conferencing, auto-transcribing and screen sharing. Serendipitous meetings at the water-cooler with your human and AI teammates.
MPC-HC - MPC-HC, the free, open source media player for Windows. DownloadsNote. Supported Operating Systems: Windows® XP SP3 .
openmeet - Account free video conferencing with a rooms component that lets you use VC within a physical meeting room. The server can also be hosted in your own cloud for extra privacy/security.