Let me recommend aPuppet which works on Android 7 and above. This project has been developed by our team especially for self-hosted remote support.
It is completely open source, the code is available on GitHub (Android app and server).
The app doesn't require adb or rooting for screen mirroring and remote control. It isn't sensitive to the device model and ...
If you want a slick and professional app, look into TeamViewer, which is available for Windows, Linux, Max, Android, iOs, Chrome OS and Raspberry Pi, which ought to cover all possibilities.
It is free for non-commercial use.
TeamViewer will let you have remote access from one device to another and will let you use the keyboard/mouse/touch controls of the ...
You can use BigBlueBUtton software. It is a free and opensource web conferencing software. there is no limit to share the number of webcams in a session.
OpenMeetings is the another opensource, web-based software. It provides screen sharing facility as well. It has been downloaded over 250,000 times.
Mconf is an open-source and free web conferencing system....
The recomendations made by @cris (accepted Answer) are great.
Especially Teamviewer is great for use in non-commercial mode. If you use it for commercial tech support it can feel a bit pricey (this depends on where you live).
We´ve used Logmein and it's also great but as far as I can tell you do need to use a paid subcription.
I would also suggest SupRemo ...
There is another music player backend called Music Player Daemon (MPD). You can find binaries for Windows and Linux. There is a Web interface, however I did not try it. Instead I used iPhone to control the daemon.
I've managed to install MPD on the ASUS Tinker Board powered with Armbian and control it with MPD Pilot iPhone app.
The installation was easy:
Well, all these years later someone upvoted which reminded me of this question. There is one way to do it that I've found that works.
First, use RDPWrap to enable multiple RDP sessions if you have not already. Create as many Windows user accounts as you need.
Keep RDP graphical context alive while minimized 
Find the registry keys: