The manager does most of the work of initiating new documentation projects and is in charge of making sure that a piece of documentation stays up to date once it's written. The manager will usually be a DC employee, but also may be a community member. The author writes some or all of a piece of documentation. A documentation project may have more than one author and authors may join and leave the project. An author may be a DC employee or a community member.
Editors work closely with writers to hone a piece of documentation.
A documentation project may have more than one editor and editors may join and leave the project. Often the manager may also be an editor. The Zope developer is someone who changes Zope. The developer will usually be a DC employee, but also may be a community member. The developer initiates changes that require documentation maintenance.