Social Source Commons

Drupal module which keeps track of things users do on a Drupal site and provides mini-feeds of these activities.

Advanced Profile Kit is a Drupal module that provides building blocks for putting together fancy user profile pages like those commonly found on social networking sites.

Drupal module that provides a user interface that allows administrators to dynamically build Apache Solr search facets without writing any code.

Backup and Migrate is a Drupal module that simplifies the task of backing up and restoring your Drupal database or copying your database from one Drupal site to another.

Drupal module for detecting browser capabilities.

Interesting for various use cases including mobile.

Composite Layout is a Drupal module that allows your nodes to be displayed in complex layouts. Currently, two and three column layouts are provided. You can also add other nodes, blocks, and even CCK fields to your node's layout.

This is the Drupal module to use for extending user profiles with custom fields. Stores profile information in nodes and supports Views/CCK.

Diff module for Drupal (need to get more details...)

Drupal model providing flexible, customizable flagging system. Supports any number of flags for nodes, comments, or users for purposes which include bookmarks, marking important, friends, or flag as offensive.

GoAway is a dirt-simple, light-weight "Ban By IP" Drupal module. It works by redirecting offending anonymous users to a local page or remote URL specified by the admin.

The Login Toboggan module for Drupal offers several modifications of the Drupal login system with important features and usability improvements.

Profiler is a set of helper functions that aid in creation of Install Profiles. It allows you to quickly and easily create new install profiles, as well as have 'Sub' Profiler Install profiles, where one Profiler Install profile inherits from and extends another Profiler Install profile.

The Skinr module for Drupal allows the theme to define a set of reusable and modular CSS styles, and to make those styles available in Drupal's UI. Skinr was developed for themers to allow them to tap into the power of Drupal's modularity and apply those same principals to theme development.

A Drupal module to help with staging/deployment of Drupal sites

The Strongarm module for Drupal gives site builders a way to override the default variable values that Drupal core and contributed modules ship with. It is not an end user tool, but a developer and site builder tool which provides an API and a limited UI. This module can be used in conjunction with Features and Profiler to build a Drupal distribution.

The Total Control Admin Dashboard module provides a souped-up admin panel for Drupal

The Views module for Drupal provides a flexible method for Drupal site designers to control how lists and tables of content are presented.