When you write libraries such as the RDF ones I do in C, you normally can never fill in the Screenshot field in freshmeat or other general software site. A while back I made an example GNOME (gtk2) GUI program for my Raptor RDF parser, more as a learning exercise although I have been making it the default helper for the RDF mime type application/rdf+xml. I've just updated it to add Turtle and also show the errors and warnings a parse might bring. So here it is, an RDF Parser GUI:
I decided to make a screenshot without errors shown to reduce any embarrassment to the victim :)
I must make a proper Redland desktop app sometime that allows manipulation of the graph. Such an application would be mostly for the developer since this would be showing application data that should not be seen by the typical end user in this form, just like XML angle-brackets.