(What was the earliest version? I know it's lower than 0.2.5.)
(Details needed especially for versions 0.4.x and 0.5.x.)
Also, the default user scripts that were bundled with Greasemonkey by default until this point were removed.
- Edit button in the manage dialog.
- Monkey icon in the status bar, click to enable/disable.
- GM_getValue, GM_setValue
Primarily bugfix release.
May 12th, 2005 
- ".tld" support in @include/@exclude, allowing things like
@include http://www.google.tld/for all international permutations.
- Log level option for GM_log
- Minor enhancements and bugfixes.
Security flaw release. Contained no fixes, rather removed all vulnerable features. Intended for (limited) continued use while fixes were being performed.
The 0.4 branch was an internal development version, where experimentation for security fixes happened.
The first release containing security fixes over 0.3.5 intended for public consumption. "Greasemonkey 0.5 is actually the combination of a massive security audit and all the new code which was planned for 0.4."
- Enhancements to GM_registerMenuCommand: keyboard shortcuts, stability.
- Memory leak fixes.
- "New User Script" menu item, shortcut to a new blank template for user script authors.
- Restricted GM_xmlhttpRequest from accessing local
- Security fix wherein a user script could elevate itself to chrome privileges.
- User can select the editor to use for "Edit" in manage, and "New User Script".
- Unicode support for non-english characters.
September 1st, 2005 
September 12th, 2005 
- Compatibility with Firefox 1.5.
- The Monkey Menu, a context menu for the status bar item added in 0.3 beta.
- Simplified script installation dialogs.
July 28th, 2006 
- Compatibility with Firefox 2.0.
- Foreign language support for Czech, Dutch, and German.
October 16th, 2006 
- Spiffy new installation dialog which more closely resembles the extension installation dialog, and presents more details in a user-friendly way.
- Spanish language support.
February 7th, 2007 
- Fixed the manage dialog so that it doesn't bounce around when you select different user scripts (thanks Anthony Lieuallen)
- Added Basque translation (thanks 3ARRANO)
- Updated German translation (thanks Matthias Bauer)
- Middle-click on monkey icon now opens manage dialog, right-click on scripts in monkey menu opens them in an editor (thanks LouCypher and pile0nades)
March 17th, 2007 
- Rewrite of 'New Script...' UI. It now pops up a nice UI to get the script details and then generates and opens a script which is already installed that you can edit in one step. This is a huge improvement in the usability of this feature. Thanks to Anthony Lieuallen for the implementation.
- Improvements to error reporting. Most types of errors in user scripts now give the correct line number in the error message. You can also click on the filename in Firebug to view the script, as with other types of errors in Firefox. Anthony is also responsible for this improvement.
- Added support for overrideMimeType to GM_xmlhttpRequest. Thanks to Lior Zur for the patch. To use, add overrideMimeType: "yourmimetypehere" to the object you pass to GM_xmlhttpRequest.
- New translations for Finnish, Japanese, and Russian. The Greasemonkey UI looks particularly cool in Japanese. Thanks to Tommi Rautava, Hisateru Tanaka, and Александр Соколов for their contributions.