Plone support for z3c.relationfield
Layout mechanisms for Plone
Versioning for Plone
Upgrade machinery for Plone.
Siteimprove integration for Plone
Plone Mosaic Tile for A/B Testing content changes
Diff tool for Plone
Default Content Types for Plone 2.1-4.3
User-configurable, blob-aware image scaling for Plone.
ZODB blob support for Plone
A PAS plugin which can manage local roles via an adapter lookup on the current context
Zope catalog index for paths
Plone addon that creates a slider viewlet containing related content.
Installation and migration support for five.intid within Plone/CMF
A small Zope 3 package (which also works with Zope 2.10+ and Five) that allows you to attach ratings to content.
Plone support for the contentratings package
An Archetypes widget that controls the vocabulary or display of otheer fields on an edit page
Zope2 support for zope.intid
A custom folder ordering implementation, which stores order persistently, but sorts content based on a rule.
Integration of Zoom.it hosted image zoom in plone.
Timeline views for collections and folders (using verite TimelineJS).
Content product for creating multi-section exhibits for museums and similar sites
A registry and adapters for converting urls for various video sharing sites into embed codes.
A set of components to provide a content centric API for the engine from plone.relations, as well as a few different core relationship types and policies.
ATField for plone.relations
Tools for defining and querying complex relationships between objects
A python library for using National Public Radio's API (http://www.npr.org/api/index)