This is my work with xournal in implementing the ability to export the journals to PNG files and svg.
For the png's each page is printed to a single png file.
For the svg it implements tiny 1.2 draft and mantains most of the structure from xournal while also providing a valid svg file.
If you have any questions or complains please submit them.
Warning: The svg file is not usable with inkscape but renders fine in others. It does not support <page> and <pageset> tags