Is Microsoft also admitting that the way they manipulated ISO for the OOXML "standard" was unethical?

And BBB is open-source.

I see that a couple of other people have selected BigBlueButton. I have used it for teaching for a long time and it's really excellent. I think we need to differentiate between tools for convincing people of things (sales tools) and tools for conveying information (teaching tools). BBB is well out in front in the latter category.