two datasets for DBLP

Hi,
   I am trying to do an alignment task between LOD datasets and came to see
that DBLP has two different datasets hosted in two places possibly with
different schemas. Following are the two URLs of them.

http://dblp.l3s.de/d2r/ [1]

http://dblp.rkbexplorer.com/ [2]

both these datasets have DBLP publlications but use different schemas for
presenting facts. Most of the time [1] has sameAs links to [2] and also [2]
to [1]. Anybody know why there are two datasets or maintain two datasets
for same information. Is any of these is complementary to the other?

-- 
Regards
Kalpa Gunaratna