/usr/include/ZenLib/ is in libzen-dev 0.4.34-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ZenLib/BitStream.h
/usr/include/ZenLib/BitStream_Fast.h
/usr/include/ZenLib/BitStream_LE.h
/usr/include/ZenLib/Conf.h
/usr/include/ZenLib/Conf_Internal.h
/usr/include/ZenLib/CriticalSection.h
/usr/include/ZenLib/Dir.h
/usr/include/ZenLib/File.h
/usr/include/ZenLib/FileName.h
/usr/include/ZenLib/Format/
/usr/include/ZenLib/Format/Html/
/usr/include/ZenLib/Format/Html/Html_Handler.h
/usr/include/ZenLib/Format/Html/Html_Request.h
/usr/include/ZenLib/Format/Http/
/usr/include/ZenLib/Format/Http/Http_Cookies.h
/usr/include/ZenLib/Format/Http/Http_Handler.h
/usr/include/ZenLib/Format/Http/Http_Request.h
/usr/include/ZenLib/Format/Http/Http_Utils.h
/usr/include/ZenLib/HTTP_Client/
/usr/include/ZenLib/HTTP_Client.h
/usr/include/ZenLib/HTTP_Client/HTTPClient.h
/usr/include/ZenLib/HTTP_Client/HTTPClientAuth.h
/usr/include/ZenLib/HTTP_Client/HTTPClientCommon.h
/usr/include/ZenLib/HTTP_Client/HTTPClientString.h
/usr/include/ZenLib/HTTP_Client/HTTPClientWrapper.h
/usr/include/ZenLib/InfoMap.h
/usr/include/ZenLib/MemoryDebug.h
/usr/include/ZenLib/MemoryUtils.h
/usr/include/ZenLib/OS_Utils.h
/usr/include/ZenLib/PreComp.h
/usr/include/ZenLib/Thread.h
/usr/include/ZenLib/TinyXml/
/usr/include/ZenLib/TinyXml/tinyxml.h
/usr/include/ZenLib/Trace.h
/usr/include/ZenLib/Translation.h
/usr/include/ZenLib/Utils.h
/usr/include/ZenLib/Ztring.h
/usr/include/ZenLib/ZtringList.h
/usr/include/ZenLib/ZtringListList.h
/usr/include/ZenLib/ZtringListListF.h
/usr/include/ZenLib/int128s.h
/usr/include/ZenLib/int128u.h