Chapter 1: Introduction

What is Plone?

Plone is a free, open source Content Management System. The focus of Plone is to provide value at every level of an organization. It comes with a workflow engine, pre-configured security and roles, a set of content types and multi-lingual support. There are many developers, writers and testers from all over the world, contributing to Plone everyday. Plone is based on the Content Management Framework.

Homepage: www.plone.org

What is a Content Management System?

Finding a definition for what a Content Management System (CMS) is seems to be harder than finding someone willing to sell you one. Simply put a CMS allows you to manage content, usually for a web site. The main goals of CMS are to allow easy creation, publishing and retrieval of content to fit a business needs.

"The trouble with content management is that its trivial or impossible."

Quote: from OSCOM, 2002

One common dividing line between different CMS's is the integration of the web and hence can two types of systems: a web based system, and non-web based system. Plone is a free, open source web based CMS

Why use a web based CMS?

Credit: Marco Federighi

The easiest way to understand a CMS like Plone is to compare it with a standard web site design tool, like Macromedia Dreamweaver. In both cases pages can be produced on a remote computer, and submitted for approval and publication. There are, however, four key differences:

any user with the required permission can produce web pages from anywhere, using any standard browser, with no need for any specialist software. A CMS is easier to use than Dreamweaver and FTP, therefore very little training is needed, and many more production tasks can be allocated to unskilled staff. As a consequence, a CMS empowers more users to create and edit content on the Web. Also, less training and lower skills result in lower production and maintenance costs.
pages are produced by typing text and uploading files into the site's pre-produced templates. This results in a more consistent corporate style. Thus, even though the number of people producing web pages for direct publication can be large, consistency of style and, more importantly, consistency in content structure is ensured.
control of workflow in a CMS can be very finely grained, with the Webmaster's job being effectively devolved to many people working in different places without any lowering of security and, more generally, of quality standards.
different versions of a document are automatically saved, resulting in a natural audit trail when required.

These benefits of Content Management Systems are obviously more significant for large organisations, or large collaborative projects, than for small businesses or organizations.

What is the Content Managment Framework?

The Content Managment Framework (CMF) is an application that contains a series of tools for Zope. These tools form a framework that provide many of the key services a Content Management System would need. The CMF can be used as a standalone product, or in Plone's case, built on top of. The CMF provides core tools like Workflow, Personalisation and Cataloguing. The CMF development is lead by Zope Corporation and is an open source product that benefits from the input and hard work of many developers around the world.

Homepage: cmf.zope.org

What is Zope?

Zope is a open source web application server, written in Python. It is a scalable, stable, powerful system that includes an object database, a web server and several templating languages. Zope is developed and supported primarily by Zope Corporation, but also by many developers worldwide.

Homepage: www.zope.org

Why use Zope and Plone?

Credit: Marco Federighi

Zope and Plone are Open Source Software (OSS), that is, the source code is available to anyone for free. The business model of the people who produce Zope and Plone relies on earnings from consultancy services, chiefly for customisation and enterprise use. Other examples of open source CMSes are Midgard, Bitflux, OpenCMS, and Wyona.

Proprietary and open source CMSes are technically not very different. In both camps we find very good, mediocre and poor products; the quality of the documentation and support also varies widely. The main difference is that open source CMS are produced by rather smaller companies than proprietary ones. This raises doubts on the long-term continuity of these firms, and of the support that they can provide. In my view, however, the difference is more apparent than real. Open source producers are smaller and thus more vulnerable to, say, the loss of one customer or the departure of a key individual; proprietary producers are bigger, but are affected by takeovers (e.g. Allaire, by Macromedia) and the vagaries of the IT stock market (e.g. Broadvision). All in all, BOTH kinds of producers can easily disappear. The difference is that, with an open source product, the source code is available to the user and so is the possibility of maintenance, customisation and development, none of which is available to users of proprietary systems without the active intervention of the producers. This is the key reason to use an open source product.

Why Plone and Zope rather than other open source CMS? Plone is based on Zope, which is a framework for building content management software. In a sense, Zope is an operating system for web applications, one of which is CMF (Content Management Framework), an application to facilitate the building of CMSes. Plone is one such CMS, based on CMF, running on Zope, but with its own set of templates and file types. In our view ("our" meaning the view of the CMS Working Party set up by the Web and Internet Steering Group, WISG), Zope is significantly better than other competing products for the following reasons:

Zope is object-oriented, in the sense that everything appearing in a Zope web site (web pages, images, links, files) is an object and is contained in an object database. The database is hierarchical, not relational, and is particularly suited to hierarchical file structures. Technical people think of databases in terms of collections of tables of rows and columns, related by primary keys. This is different, and mirrors much more closely the structure of an ordinary file system, with objects within objects.
The Zope database contains all older versions of an object: this is particularly useful for undoing changes, for the control of versions of collaborative documents, and for items requiring an audit trail.
Zope contains a number of tools that are specially suited to large organisations and collaborative work, and will be described later in the manual. One example: pre-defined database searches, based on flexible search criteria, which automatically display all objects satisfying certain user-specified conditions.
Zope can be used an all platforms: Unix, Linux, Mac OS, and all flavours of Windows (98, 2000, XP, NT). This is not true of most other CMS, open source and proprietary alike.
Zope is a very friendly developing environment. The possibility of creating a customisable copy of a script at the touch of a button, while keeping the default version in its original location, is the best safety net I have ever come across.
In Zope it is easy to design structured XML documents, with workflow linked to the document structure. This is an essential feature for the administrative systems in a large organization, and promotes both corporate consistency in the style and structure of documents and a streamlined work flow.
Finally, Zope was created for use by large organisations, with the following characteristics: large number of contributors to collaborative projects, with contributors located at different sites and using different platforms; strong organisational requirements for flexibility and security, with the need to define local roles with different permissions to view, write, edit and approve different parts of large projects; scalability to large numbers of objects and servers.

The seventh, cultural difference between the Zope team and their competitors is crucial for large organisations. One of the Zope customers is the US Navy, which uses Zope for the management of R&D projects: a big, public-sector organisation with a keen eye on flexibility and security. The same could be said for most large corporations, public as well as private.

As far as Plone (as distinct from Zope) is concerned, I regard it as rather more than a generic CMS that happens to be based on Zope. Plone adds to Zope at least two very useful features, which are especially important for the purposes of the Engineering Sciences web site:

A neat, elegant framework for navigation, relying on folders and the viewing of their content rather than links in html documents (which would have to be updated) and aided by navigational shortcuts such as the Bulletin (which displays objects created or modified within the last few days, thus eliminating the need to navigate the site to find them).
A simple tool for the creation of complex structured documents such as PIQ and UPC forms, with different parts of each documents visible to different audiences and a customizable approval path.

The first feature makes a Plone-based site uniquely easy and fast to use; the second makes it useful for administration, unlike most CMS which are conceived primarily for the publishing rather than the processing of content.

What is Python?

Python is a powerful, interpreted, interactive, object-oriented programming language. Python is open source and can run on almost any platform or system. Zope is written primarily in Python, with some optimisations in C.

python, (Gr. Myth. An enormous serpent that lurked in the cave of Mount Parnassus and was slain by Apollo) 1. any of a genus of large, non-poisonous snakes of Asia, Africa and Australia that suffocate their prey to death. 2. popularly, any large snake that crushes its prey. 3. totally awesome, bitchin' language that will someday crush the $'s out of certain other so-called VHLL's ;-) *

Quote: "What is Python" from python.org

Homepage: www.python.org

Who is this book aimed at?

This book is aimed at people in several different roles including:

the system administrator
the site content manager (who oversees adding and publishing content)
the site member (the person who joins and may be adding content)
the site developer (people who person who writes HTML, or code)

What version of Plone does this cover?

This book covers the latest release of Plone as downloadable at Plone.org. It does not cover the CVS version or earlier versions. It also covers a "default site" as defined by the customisation policy. Whilst other versions such as the "private site" may exist, this is not covered here, however most of the concepts are the same.

Feedback

If you have feedback we'd love to hear it. The best thing you could do is send us an email to the documentation mailing list and someone will reply.

Page Editor: Andy McKay $Id: 1,v 1.4 2003/06/23 05:11:19 zopezen Exp $

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