MathML https://developer.mozilla.org/en-US/docs/Web/MathML/Authoring

viewport http://webdesign.tutsplus.com/tutorials/quick-tip-dont-forget-the-viewport-meta-tag--webdesign-5972

viewbox http://svg.tutorial.aptico.de/start3.php?knr=3&kname=Do...&uknr=3.5&ukname=Das%20Attribut%20viewBox