This is not the actual beta. These are just nightlies tagged as the beta (the version string was updated to 'beta') for testing purposes. This same story showed up on Slashdot and Mozilla's Asa Dotzler commented on it: http://news.slashdot.org/comments.pl?sid=1702398&cid=327...

You can find the Firefox 4 Beta when it's actually released here: https://www.mozilla.com/en-US/firefox/all-beta.html

Interesting that when you launch the windows installer, it says nothing about firefox, it says Installing Minefield

Is this some quirky pun on the fact that it is pre-release software? Or is there a more general name change in the works?

[edit] Seems it is due to the testing process - http://www.mozilla.org/projects/minefield/ WARNING: THIS IS NOT A FINAL VERSION OF FIREFOX and then goes on to say:

This program is provided without any guarantees of stability and you should back up your profile regularly as there may be bugs that corrupt your data. If that sounds scary, please use the latest version of Firefox.

They've always used Minefield for nightly and alpha builds.

"Minefield" is the name given to the Firefox nightly builds.

This includes WebSocket support - which seems to work great :)

Well done Firefox team!

I've been using the nightly's for the last 3 weeks and they've worked great without any crashes. I'd recommend upgrading if you're comfortable with beta software as I believe most of the big bugs have worked out. The only major bug I've noticed is that using right click and selecting 'back' doesn't always work.

The latest build moves the tabs to the top which is an interesting change and takes some time to get used to.

It's interesting how FF and IE now differ in layout from top down:

FF: Title Bar, Menu Bar, Tabs, URL, Bookmark Toolbar (default hidden) IE: Title Bar, URL Bar, Menu (default hidden), Tabs

I'm away from my desktop for another week: my only question is if they've put any thought into speeding up startup times and/or improving the UX and design on Macs. Firefox used to be great, but it's really fallen behind in terms of speed and usability. I hope this changes that.

EDIT: Thanks for the replies! I'll be giving it a try again. It's good to have choices.

Here are the design mockups for how Firefox 4 should eventually look by default on Mac OS X: https://wiki.mozilla.org/Firefox/4.0_Mac_Theme_Mockups

These designs are not fully implemented in current nightly builds, and are subject to change. Also, here are the Windows and Linux mockups:

https://wiki.mozilla.org/Firefox/4.0_Windows_Theme_Mockups

https://wiki.mozilla.org/Firefox/4.0_Linux_Theme_Mockups

There are quite a few performance improvements going into Firefox 4, with a strong focus on startup time. See http://autonome.wordpress.com/tag/startup/ for detailed tracking of Firefox startup improvements.

I wish there were a version with less chrome and more web real estate - I've thinned my current version down as much as I can really (Cool Menu 2 FTW) but the tab height is about twice the font height and the menubar (in which I have my location and search bars) is twice the icon height. Why waste all this space - I understand negative space but really this seems to be too much form not enough function, browser chrome should be as slim as possible but still usable IMO; if I use a small font it should be smaller.

Even the latest stable release (3.6.6) starts just as fast as Chrome for me (I use an ad blocker, bookmark sync and firebug in both browsers). Firefox has been painfully slow in the past, but it seems okay now, although its UI is still rather clunky.

The chrome of Firefox is better now: the line between the bookmarks bar and the navigation bar is no longer here and the buttons are squared. It really looks like Safari, wich is good for minimalism and Apple-compliance, but sad for diversity and innovation.

I really enjoy this update, BUT do not enable the "tab on top" feature. It's not fully implemented yet and it's really ugly.

(I have also the two icons issue.)

Another detail who moves Firefox closer to Safari : text in the bookmark toolbar now turns to white when hovered.

The default 3.6 theme is pretty ugly, but there are some great replacements. I'm using one called Camifox.

http://imgur.com/Sm3Ld.png

https://addons.mozilla.org/en-US/firefox/addon/7527/versions...

The Mac UI _looks_ better; for some reason, though, I'm getting two icons in my dock, occasionally.

I see virtually nothing noteworthy on http://modernizr.com in these 4.0 pre-release builds — no real new HTML/CSS features, no 3D transforms, etc.

Yeah, a lot of our engineering effort is going into performance right now, rather than new features. But here are some of the HTML and CSS features in Firefox 4:

- HTML5 parser (SVG/MathML in HTML, new semantic elements)

- HTML5 forms (only partly implemented so far)

- Web Sockets

- CSS3 transitions

- CSS3 calc()

- IndexedDB (schemaless client-side database)

- WebM (VP8) codec for HTML5 video

- SVG backgrounds and images in CSS and HTML

- ECMAScript 5 features in JavaScript

Does 3.7 == 4.0? Or hasn't the new UI been pushed to the nightly builds yet? (at least for OSX)

Yes, the 3.7 release was renamed to 4.0. See http://beltzner.ca/mike/2010/05/10/firefox-4-fast-powerful-a... for details. Not all of the new UI is in nightly builds yet (much of it is just finishing the design phase).

You need to set extensions.checkCompatibility.4.0b=false

I don't care what their rationale is, the version numbering ideology of the mozilla foundation is dumb. There's not a good enough reason to stick to version 3.7 for a "version 4" beta, it's super annoying and makes them look amateurish.

The next version was originally going to be called 3.7, but it was later renamed to Firefox 4.

Starting with beta 1, there will be no more references to Firefox 3.7. As we speak, all version strings are being updated to refer to 4.0 instead.

They have clear roadmaps for each major version number. I'm not so sure I'd consider it dumb.

It's fine as long as you keep consistent naming. Calling 3.7 version 4 is dumb, if you're going to call it 4 then bump up the version number, if you're not going to bump up the version number until later then stop calling it 4.

They're calling it 4. This isn't the official beta. The 3.7 are just old executables lingering in the FTP folder.

firefox-4.0b2pre.en-US: http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/lates...

Seems to be working very well: http://cl.ly/1W6b

That's a custom theme. Disable that and it should be fine.