In addition to Plone's built-in tools, this chapter will explore the capabilities of several third-party add-ons. Open-source software is often called "free as in beer" or "free as in freedom". As typical of Plone add-ons, the products we will consider are both. However, they are also "free as in puppies".
Who can resist puppies? They are heart-meltingly cute and loads of fun, but it's easy to forget, when their wet little noses are in your face, that they come with responsibility. Likewise, add-ons are free to install and use, but they also bring hidden costs:
Products can hold you back. If you depend on one that doesn't support a new version of Plone, you'll face a choice between the product and the Plone upgrade. This situation is most likely at major version boundaries: for example, upgrading from Plone 3.x to Plone 4. Minor upgrades, as from Plone 3.2 to 3.3, should be fairly uneventful. (This was not always true with Plone 2.x, but release numbering...