In this appendix, we're going to summarize the contributed modules we've used in the book and present a listing of modules that allow for integration between Drupal and web service applications and servers. This chapter will present a concise and organized listing of modules that access remote servers and services, and that integrate and install with the Drupal content management framework. This chapter will serve as a cheat sheet and summary for you to use during your Drupal-based projects. All modules used in the book are listed and summarized here.

For more information about using Drupal modules, you can visit the main drupal.org Modules repository at: http://drupal.org/project/Modules. Modules are listed by popularity, category, and compatibility. There is a search box that allows you to search for specific modules by keyword and also a sort filter that allows you to search by relevance, most installed, author, and more. Here, you will find modules listed with a summary of what the module does, and a table showing the versions, date of last update, status, and links to download the module. There is also a link provided that points you to a full index of all Drupal modules available at: http://drupal.org/project/modules/index. This index lists all 6,000+ modules in alphabetical order.

Another good Drupal module resource is Drupal Modules at drupalmodules.com. This site is an open source community-driven project that lists, rates, and reviews all Drupal modules. This site allows you to search for modules and restrict your search to Drupal versions. It highlights new modules and contains a blog that posts interesting modules, related news, and case studies. It presents links to the highest rated and most downloaded modules. For example, in September 2010, the most downloaded module according to Drupal Modules was the Administration menu module, closely followed by CCK. If we do a search on Drupal Modules for the Twitter module, we get a page that shows the detailed ratings for the module, a module overview, and download links.

I'm also including a link to the usage statistics page for each module via Drupal.org. Usage statistics show how often the module is being used on a weekly basis. You can see the number of downloads for the module in both the 5.x and 6.x versions for each week since the module was released and also stats on the usage per module release version. This is interesting data in that it shows that the majority of modules are seeing steady growth in usage and downloads over time. Here's an example of what a usage statistics graph for the Amazon module looks like:

To summarize, in this chapter we will: