The font family Liberation Sans is a free font, and mentioned in the compatible fonts list : https://meta.wikimedia.org/wiki/SVG_fonts. But this font don't work and is badly rendered by Wikimedia Commons render system : see https://commons.wikimedia.org/wiki/File:Text_test_file.svg and https://commons.wikimedia.org/wiki/File:Isotope_CNO.svg for example.
Do you know where does this bug come from ?