Highlight text with SVG 1.1

I need to find a way to highlight text using SVG 1.1. The attached file "[login to view URL]" displays the results I want to see. But we had to set the all the text and rectangle positions by hand. I want a way, in SVG 1.1, to create the same output without any manual work. To be clear: I want an effect in SVG which is like <span background-color=…> in HTML. I will test that a solution works by adding or removing letters from some of the text phrases. I will expect the background boxes to adjust to match the new sizes of the text. In order to succeed, and for me to accept your work, this test must pass on all four of the following platforms: Firefox, Chrome, Apache FOP 1.1, and inkview/inkscape. Hint: We suspect that SVG filters may be one way of doing this. I have attached some experiments that almost work, in the file "filter-experiments.7z". [login to view URL] was the most promising candidate, working in inkview/inkscape and in Apache FOP, but not in Firefox and Chrome .