Standards Support Enhancements & Layout

• CSS 2
  
• Mozilla now has support for CSS2 quotes (bug 24861).
• Drop-caps rendering (with first-letter) is much better (bug 21616).
• Support for url cursors (bug 38447)
• The 'outline' property, 'outline-style', 'outline-color', and 'outline-width' have been enabled (bug 281972) and (bug 6647)
• Fixed major issues with when 'clear' interacts with collapsing margins (bug 209694)
• Fixed major issues with floats and pagination causing crashes or incorrect output (bug 263825)
• Added support for CSS2 counters (bug 3247), which includes the 'counter-reset' and 'counter-increment' properties and the'counter()' and 'counters()' values of the 'content' property
• CSS 3
  
• Experimental support for CSS3 columns enabled (see bug 251162).
• Support for CSS3 cursors has been added to Gecko (bug 163174).
• Support for current color (bug 216559)
• The 'outline-offset' property has been implemented (bug 251498)
• CSS Extensions
  
• Mozilla now supports the overflow-y and overflow-x properties (bug 72747).
• Mozilla now supports a at-rule for matching on site/document URL. Among other things, this makes site-specific user style rules possible (bug 238099).
• Mozilla 1.8 offers CSS error reporting via the JavaScript Console. (bug 65469).
• DOM
  
• Undetected document.all support has been added to Mozilla. (bug 248549).
• Mozilla now has support for exposing elements by their ID in the global scope for greater IE compatibility. This is quirks mode only. (bug 256932).
• Layout
  
• A lot of problems with content flashing in several locations during reflow were solved by bug 238493).
• Resizing the window no longer lays out background tabs (bug 227361).
• We paint now the borders in border collapse mode (this is also triggered when frames, rules or groups are specified on tables, and ms excel uses it for html export) more correctly when we are in rtl mode (arabic, hebrew language). Just compare the testcases in the bugs with ff 1.0 to see what this means. This got fixed by (bug 174470) and cleaned up by (bug 267420).
• Bug 280711 brings a fix for displaying long blocks on Windows (excluding Windows 95, 98, ME).
• Bug 201897 -- layout of auto-width absolutely positioned elements wrong.

Miscellaneous

• Untrusted documents can no longer load images from the user's hard drive (bug 69070).
• All known problems where view-source would not display some of the characters in the page (such as misplaced quotes) are now fixed. (dependencies of bug 57724).
• Some parsing errors are now marked in red in view-source.

Mozilla Toolkit

• The XUL Tree widget has undergone significant changes. You read more about that here.
• Mozilla has support for translucent windows on Windows and GTK2. (bug 252067 and bug 252525.)
• The XTF framework was enabled (bug 269859).
• The "save as" code was changed to not use HEAD, fixing a whole slew of issues (bug 160454).

Mozilla Core

• The number of cookies Mozilla will hold has been dramatically increased and a hidden pref added for the few users who need even more.
• Mozilla 1.8 Alpha2 has initial support for the new Netscape Plugin API extensions annouced in the recent press release. See the Scripting Plugins in Mozilla document for more information."
• The new npruntime plugin scriptability API has been added to Mozilla 1.8a3 (bug 250666.)
• Gecko's DHTML performance has had some major improvements over the last two alpha milestones.
• Persist printer settings when printing from web page using window.print() command (bug 156992).
• Fix for bug 212034 makes printing long tables behave much better and more consistently (cross-platform).
• New permission manager back end landed.
• Major improvements to textarea parsing: bug 88952 and various dependencies
• The XML parser used by Mozilla was upgraded to a newer version (from Expat 1.2 to Expat 1.95.7). Because of that upgrade, Mozilla complies better with both the XML specification and the Namespaces in XML specification. Starting with 1.8a6, Mozilla will reject some invalid XML documents that it used to accept in prior versions. This has already led to some problems with extensions that used invalid XML documents, but the only solution is to correct those documents. Here are some of the wellformedness errors that Mozilla catches since the upgrade: - Invalid entity names (for example entity names containing a colon) - Undeclared prefixes - Multiple attributes with same localname and different prefixes bound to the same namespace names - Redeclaration of reserved prefixes and namesapce names
• E4X (http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-357.pdf), except for the DOM binding magic, which is coming in 1.8b2.