CoCalc is probably the best outcome of collaborative opn source efforts as of today. It is a collaborative online computing environment, mostly for Sage (an open source mathematical software). Apart from sage worksheets, it allows octave, jupyter notebooks, latex and R document editing, and many more. You can just create an account in their website and start using right away.
But the best part is that you can install Cocalc as a server and let others log in to it and collaborate. No need to install sage or sagemath.
Follow the instruction to install the cocalc-docker. It is just one
line long code. It will download,
extract and install. I had to use sudo to get it to work since I
installed docker using sudo (sudo apt-get install docker.io).
To open it in browser, make sure to use https://localhost instead of
http://localhost.
I had create account (fake email ids are ok, since they are local)
To start and stop cocalc, use
sudo docker start cocalc
and
sudo docker stop cocalc
view(). To
print out the latex code of it, use the function latex().To turn the latex rendering on by default, you can use %typeset_mode to True at the beginning of the sheet
u_th_x = var('u_th_x', latex_name = 'u_{\\theta}(x)'}
Later, do view(u_th_x) to see it rendered correctly as
\(u_\theta(x)\).