19 Jan
                
                    2012
                
            
            
                19 Jan
                
                '12
                
            
            
            
        
    
                7:53 a.m.
            
        You could use Xerxes-C for C++ http://xerces.apache.org/xerces-c/.
For Python, you could use http://docs.python.org/library/xml.dom.minidom.html or http://lxml.de/
SVG data is stored as elements in an XML document, so you don't need inkex to read, update, or even create the SVG/XML file. XML tools will let you parse the file in, search for the tags & values you want, and update them.
- Susan