User blog comment:Harbumz/Introducing Vignette, Wikia's New Thumbnailer/@comment-34115-20150212010632/@comment-34115-20150212071745

Wikipedia is using rsvg.

ImageMagic is the default simply because defaulting to poor SVG rendering is better than defaulting to no SVG rendering when a SVG renderer hasn't been configured. It's essentially the same reason we default to crappy GD based image thumbnailing when ImageMagic hasn't been configured.

That manual page gives this description for ImageMagic SVG rendering "Since version 6.x.x ImageMagick renders SVGs, but imperfectly. This is the default, but avoid it if possible. However, it does work."