Plone is a full-featured CMS all by itself, but it also has a rich ecosystem of add-on products that can extend it's capabilities. Here's a list of the products I've installed on this site.
- PloneFormGen - A completely reliable, supremely flexible, and remarkably simple-to-use product. It should be a standard for any site that needs form input. From the inimitable Steve McMahon.
- Collage - A wonderful tool for building more complex content views out of simple pieces. Pay no attention to the product page on plone.org. This one's a winner.
- ContentWellPortlets - Allows site creators to set up portlets in a number of non-standard locations, such as the footer, or above and below the main content area. From the great minds at WebLion.
I host this site with the friendly and helpful folks at WebFaction. I can recommend their service without reservation.