Userscripts.org

Alerts you to the status of your Gmail Inbox through distinct Favicons.

Link Color and Profile Avatar

Cleans the entire Gmail header and footer when you print. Additionally removes the message count line if there is only 1 message.

AES 256 Text Encrypt/Decrypt

Removes the people/advertisement sidebar when using the Preview Pane labs feature, as well as various other improvements.

Forces known sites to use a secure connection. Look at description for the sites that are forced to use a secure connection. And just add any sites you want to use an https connection.

Easy to add/remove "is:unread", "is:starred" to GMail search box without typing.

Fixed-font message bodies for Gmail

This tool was coded recently as of May 13, 2013 Uses a flaw in gmails password reset to reset any gmail account password to your choice.

Enhance GMail Basic HTML with "select all"

Adds strikethrough button to Gmail rich text editor

Gmail + LaTeX = GmailTeX

Implements chat and compose window resizing in Gmail similar to what is found in Google Plus. Just drag on the edges to resize windows.

This script improves Google Mail's new look to be more neat and save space with additional keyboard shortcuts (set display density to compact) [all ads & feedback removed]

User script that allows the resizing of the labels column in Gmail. To resize the left-hand column, a drag bar is added. Once resized, the size is remembered over page reloads

Remove top bar and compact margin to save screen estate.

Change Gmail's UI Font

A Javascript Library for User Scripts that makes it easier to script for GMail. Ideal for @require.

Hide search and navigation bar in Gmail. Reclaim your vertical screen space. Toggle button allows to bring back Google bars with just one click.

Hide search and navigation bar in popular Google webapps: Gmail, Calendar, Reader, Groups, Translate, and Google+. Reclaim vertical screen space. Toggle button allows to bring back Google bars with just one click.

Remove Gmail vacation responder massage on top of your gmail page

Bouton pour afficher/masquer les messages des curieux

When using the 'Preview Pane' labs feature, removes the sidebar to save space and adjusts the width of the preview pane so that there's no need to scroll the pane horizontally at low screen resolutions.

Got a silly administrator that added the Insightly plugin to your company's Gmail account? This script will remove the Insightly block below emails.

Audio & Favicon alerts for New Mails or Chat msgs. (Cross-browser compatible!)

Removes tags inside square brackets in subject lines

Displays a count of the subject field line in Gmail. Useful for Twitter posts. Tested Firefox. Updated 2 Nov 2012 to support new Gmail pop-up Compose box.

Hide all advertisements and right side frame on Gmail / Google Apps, get extra work space.

Replace http:// with https:// in the address bar, to make sure you're using the SSL-encrypted version of a page. Only enable for pages that you know are SSL enabled.