Copy and Paste now preserves RDF between both Calligra and abiword in both directions. This lets you select some text in a document in either application, copy it, and paste it into the other application and have the RDF that is associated with that part of the document go along with the text you selected.
In the below screencast, the document that Calligra is editing has some contact and event information stored in RDF. The three people in the first sentence all have contact information associated. As you can see, the RDF sidepanel in Calligra lets you know about this as the cursor moves around. James has his phone number captured in RDF which the edit dialog shows. If I select one or more of these contacts and "Copy" them to the clipboard, Calligra creates an ODF file with embedded RDF in it and offers that on the clipboard.
Abiword is happy to accept that ODF content and when you paste it into a document you can see that the RDF links are preserved, and that there are 7 RDF triples associated with James. Of course, you want full disclosure of this information, so clicking show RDF lets you examine and edit those RDF triples.
I put a little trick in going the other way just to spice things up a little bit. The multi.odt file that I have open in abiword has two RDF links in scope at the Wing-B link. RDF is associated with the whole paragraph and explicitly with the link itself. In particular, the uri:widetime is associated with the paragraph while the uri:wingb is associated with the RDF link itself. Once I grab that RDF link and copy it to the clipboard, again an ODF file is offered (as well as text and rtf), and again Calligra is more than happy to accept an ODF file on the clipboard. Notice that when I show all the RDF in Calligra both the widetime and wingb RDF triples have now become part of the document.
I made some changes in both calligra and abiword to get this to happen. Changes to the former were quite small. You'll have to grab trunk from both applications if you want to play along at home. The code is committed in both trees.