Render HTML in the Tooltips

Is there a way to render HTML markup in the tooltips?

Sure, just use HTML as your tooltip: GoJS HTML Interaction -- Northwoods Software

My tooltips fade away after a few seconds, how do I make it so they only go away when I mouse out?

This is mentioned in Page Not Found -- Northwoods Software

You can change how long the tooltip remains visible by setting ToolManager.toolTipDuration. For example, “toolManager.toolTipDuration”: 10000 changes the visible time to 10 seconds.

“Mouse out” of what?

Also, do you need to give any consideration to mouse-less devices?

Basically, when I mouse over a node, I don’t want the tooltip to vanish at all until I mouse out of the node.

Yes, I will eventually need to consider mouseless movement

Just set ToolManager.toolTipDuration to a large number of milliseconds. Infinity would be long enough, I would think.