This example demonstrates a custom web extension that extracts numeric values from specific table cells and injects them into a new visualization table with highlighted yellow data areas. The code uses native DOM APIs such as `document.getElementsByClassName`, `createElement`, and `appendChild` to manipulate the HTML structure. It also parses an XML manifest describing the extension’s parameters using `DOMParser` or the ActiveX `XMLDOM` object, outputting the parameter caption and description via `document.write`. The visualization logic itself remains mostly unimplemented, with initialization and callback functions defined but not executed.