ZEO and NEO Wendelin has the option of using two backends. The default Zope database called ZEO or NEO, a more resilient and robust version of ZEO implemented by Nexedi. Switching Default Database Both backends share the same API so any code written will work on both. When using the default installation of Wendelin as described in the documentation (coming soon), ZEO is set as default. NEO being specificially designed for distributed and resilient clusters would be the more advanced option for Wendelin. Please look at How To Set NEO as Default Database (coming soon) in case you want to experiment with using NEO as backend.