Just re-discovered
Jitsi, still one of the most interesting online video chatting solutions out there.
You don't even need to download a program anymore, just point your favorite browser to
https://meet.jit.si/, share with partners by whichever means and chat away.
On the software side,
Jitsi is FLOSS multi-platform software, available on every platform there is; just take a look at
https://jitsi.org/downloads/.
Although I haven't really tested any of the Windows builds, it looks like
Jitsi switched of late from being Java based to being Electron based, so there's still a con there -- although in the present case it might be entirely justified.
[Jitsi stands for] Multi-platform open-source video conferencing. At Jitsi, we believe every video chat should look and sound amazing, between two people or 200. Whether you want to build your own massively multi-user video conference client, or use ours, all our tools are 100% free, open source, and WebRTC compatible.
Jitsi Meet is an open-source (Apache) WebRTC JavaScript application that uses Jitsi Videobridge to provide high quality, secure and scalable video conferences. [...] On the client side, no installation is necessary. You just point your browser to the URL of your deployment.
WebRTC does not provide a way of conducting multi-party conversations with end-to-end encryption. Unless you consistently compare DTLS fingerprints with your peers vocally, the same goes for one-to-one calls. As a result, your stream is encrypted on the network but decrypted on the machine that hosts the bridge when using Jitsi Meet.
The Jitsi Meet architecture allows you to deploy your own version, including all server components. In that case, your security guarantees will be roughly equivalent to a direct one-to-one WebRTC call. This is the uniqueness of Jitsi Meet in terms of security.