The current version (6.0 at the time being) of the IPE editor is available at http://ipe.compgeom.org/. As in the time we were developing VRR there was installed the outdated version 5.0, we decided to write a really simple and basic import module to reuse the vast amount of IPE v5.0 pictures.
Writing the importer (located in import/ipe5.c) was the work of trial and error, as the IPE native format is not documented. We mention that it is a 3-in-1 polyglot. When processed by TeX it produces the TeX writings and when processed by a PostScript interpreter, the graphics is printed. Moreover, some internal IPE information is saved in the comments.
The importer is a simple text file parser, see the source for details on IPE format. The following features are not implemented:
The discovered IPE objects are inserted into the supplied TLO.