Ways to investigate for the future of Plone (Encolpe Degoute)

How can we improve Plone?

What is Plone? The simple answer: Plone is a stack upon Zope on CMF.

The more complex answer: Plone is build with Python and C with Twisted for Zope and the ZODB. It’s using some frameworks: CMF, Archetypes, Dexterity, jQuery, KSS, … It’s a CMS but it can be seen as a framework to build a web application on.

There are several layers we can improve on.


What’s the next Python to use? There are CPython 2.7, CPython 3.3, PyPy and Stackless Python. Encolpe thinks Python 3 would be a good move. We need to invest more in Python development.

Network layer

Regarding the network layer (Twisted). Some tests show that Twisted is more or less the worst framework in place for the job. If we want to replace it, we need to choose between synchronous or asynchronous. Options: Gunicorn, Gevent, Tornado. However: it will take a lot of work and it will have to be added to a next version Zope.


The ZODB is storing objects in Python pickle format. We can use a file as storage (FileStorage) or some databases (RelStorage). All transactions are stored until a ZODB pack.

Problem with the pickle format: it’s too Python centric and needs a C binding (cPickle) to get good performance. To replace pickle we can use e.g. JSON or XML. Problems with JSON: no schema validation and the binary format is not normalised. XML was created as an exchange format, but it’s now also used to store data. The problem with XML is the opposite of JSON: everything needs to be specified in a schema.

Ideas to improve the ZODB: use stratified B-Trees, use relational databases for the catalog to improve indexes and have a sub process that cleans up old transactions automatically.

Replace the ZODB completely with e.g. Cassandra or MongoDB?

[… Here I missed a bit because I got distracted by some work related issues …]

When should we switch to Bluebream (Zope 3) and ZTK? We are still not ready at the moment. Should we keep CMF or push it in the ZTK? Everyone agreed that that would be useful, but no-one wanted to do the work.

Which visual editor should we use? TinyMCE, CKeditor, Aloah, VIE and Create.js? The problem lies in the Plone integration. For instance, TinyMCE is not up to date with the latest versions of the original product.

Ideas for Plone:

  • We need to start using Dexterity and migrate all products for Plone 4.3.
  • Plone should be able to automatically create e.g. Open Documents, PDFs, …, from the existing content.
  • How can we include microformats and schema.org in a Plone site?
  • There is no Python library to connect with RESTful services.

View the slides or watch the video.