I once helped someone create a monstrosity of an SVG - they exported a flowchart SVG from Visio that would show the current state of different steps of a project. The status of each step was stored in a SQL database. I helped write some JavaScript inside the SVG that would create an ActiveX object that would open up a ODBC connection and execute a SQL query to get the latest states, which would update the colors on the flowchart every time you loaded the SVG. It would obviously only work in IE11. Plaintext credentials stored right inside the SVG!