[libvirt] Alternative to XML Creation and Parsing?

Hello, We plan to develop a fancy GUI which would help creating and managing VMs/Domains for RHEL 5.4 KVM. However looking at the schemas provided in docs/schemas/ (Ex: domain.rng) generating the XML file from the inputs taken from the GUI and pass it on to virDomainDefineXML() turns out to be a huge tasks in itself. I was wondering if there is an better way for me to provide my configurations to the library and also to read data from it (instead of creating, parsing XMLs)? If an alternate approach exist, are there any limitations with it? Also the schema given in docs/schemas/ would be generic for all hyper visor. How can I identify the tags applicable only for a particular hyper visor? I found: virConnectDomainXMLFromNative(virConnectPtr conn, const char * nativeFormat, const char * nativeConfig, unsigned int flags) in API reference, which could solve my first problem but couldn't figure out what nativeFormat would be. Any inputs/pointers would be highly appreciated. Regards, Ganesh