I am looking for solution for collaborating online with my math research colleagues using a virtual whiteboard. Unfortunately, most browser based whiteboards run out of memory or have other issues - I am talking about 3-4 hour long sessions consisting of dozens of pages of math. Right now, we take turns sharing our screens on zoom and writing on our own whiteboard software (OpenBoard, some Mac whiteboard etc.). This is less than ideal because only one person can write at a time, which is not how we work in person on paper or actual whiteboards.
The best I have found is http://www.styluslabs.com/ But our one session with it ended with repeated disconnections and one person couldn't even connect. Not to mention it is completely insecure (http connections), and the whiteboard part of the software is not that impressive.
Any suggestions?