Complex sentence: The first version of Doxygen borrowed code from an early version of DOC + + (developed by Roland Wunderling and Malte Zöckler at Zuse Institute Berlin); later, the Doxygen code was rewritten by Dimitri van Heesch.
Split into simpler sentences: The first version of Doxygen borrowed code from an early version of DOC + +, developed by Roland Wunderling and Malte Zöckler at Zuse Institute Berlin. Later, the Doxygen code was rewritten by Dimitri van Heesch.