Beginning with CWE 1.0, there are two main views that are being supported for different audiences and purposes:
CWE-699 (Development Concepts) supports developers and tool vendors, offering flexible navigation from different perspectives. It borrows from previous taxonomy efforts, so it will be familiar with many consumers. Much of the structure has been used since the beginning of CWE.
CWE-1000 (Research Concepts) supports research, using a fixed perspective that focuses exclusively on weaknesses and the different relationships between them. It is a novel approach to weakness classification that also has certain benefits to the CWE Content Team with respect to content management.
This paper performs a comparison between these views, as well as CWE-700, the Seven Pernicious Kingdoms view, which is based on the original paper published in 2005 [7PK].