The WPF version is working and should provide you with the features you are looking for.
maps to SharpVectors.Runtime namespace
or SharpVectors.Runtime.dll assembly, and it seems that is missing in your references.
[assembly: XmlnsPrefix("http://sharpvectors.codeplex.com/runtime/", "svg")]
[assembly: XmlnsDefinition("http://sharpvectors.codeplex.com/runtime/", "SharpVectors.Runtime")]
SharpvectorSquiggle is a work in progress, meant to provide complete applications for working
with SVG/WPF. Currently, not much is done on this application.
WptTestSvgSample is a sample application providing viewing features and based on the SharpVectors