Here is a list of the modules that I think are essential to most Drupal projects. I’ve tried to keep the list as succinct as possible, for a more extensive list try Nick Lewis’s post. This post is aimed at people with some knowledge of what modules are out there for Drupal. If you’re a seasoned pro you may find I’m covering old ground.

Before going into my detailed list, I’d like to briefly mention some of the more obvious modules that crop up on many of these posts. The first set of modules is the “big three”: CCK, Views and Panels. 99% of projects will use at least one of these modules. The ability to set up and theme this set of modules is essential to any Drupal developer’s toolkit – without them you will only be able to create simple Drupal sites.

In addition, there is another set of modules that are “no brainers” if you want a search engine friendly, spam free website. Pathauto, Token, and Global Redirect give you clean, user and search engine friendly URLs without any duplicate content. Mollom is a brilliant service that helps to reduce comment form, contact form, and registration form spam. It reduces the time you have to spend moderating user generated content, and above all, there is a highly featured free plan.

Without further ado, here is my list of less obvious essential Drupal modules:

WYSIWYG

Most people adding and updating content on a daily basis wouldn’t know an a tag from a div tag – for this reason you must include some sort of WYSIWYG editor. This module gives you an easy way of integrating a selection of the most popular Editors, including my personal favourite CKEditor.

SEO Checklist

This is a brilliant module for keeping track of your Drupal SEO efforts. If you check off everything in this module, you will be well on your way to having a search engine friendly site. Not only does this act as a simple checklist, the module will also tell you when each task was completed and who it was completed by. The module also provides links to download or change the settings of any modules needed for the task.

Views RSS

The module extends the functionality of the Views module so you add RSS feeds to your views. You may also want to use the Feedburner module to keep track of your feeds and provide users an easy way of adding feeds to their preferred reader.

Webform

This very useful module adds a ‘webform’ content type to your site, allowing you to add one-way communication forms such as a contact forms or surveys. The forms, email submissions and confirmation pages are fully themable. There are plenty of options for sending submissions by email and submissions are stored within the site for quick access.  

Devel

This module is a must for any Drupal theme or module developer. It gives massive amounts of information, from a summary of database queries for every page request to pretty printing arrays for theme development. In addition content can quickly be generated by the module enabling you to accelerate the development of the site even when content isn’t yet available. In addition, I like to install the The Developer module – this is almost like Firebug for Drupal. It gives you information on which TPL files and functions are used to load various parts of a Drupal page. I wouldn’t be able to create themes without it!

Nodewords

Nodewords lets you add meta tags into Drupal pages both manually and automatically. Although tags such as keywords no longer have any SEO affect a good meta description will go a long way to increasing clickthrough rates in the SERPs. There are many other types of tags available, from copyright to location tags this module will let you quickly and easily add and update them.