The latest stable version is 25.0.1
The latest version of Firefox is always considered to be "better." As of right now (3/28/2011), the latest and "best" version of Firefox would be Firefox 4.0.
Latest version Firefox 5.0 Beta 1. In my experience, It is the best.
Point your arrow to the Firefox word across the top of your screen. Scroll just one space to "About Mozilla Firefox", click on it and that box will tell you what version you have.
Yes. Mozilla Firefox up to the latest version is currently compatible with Windows 2000.
Normally you will get a notice regarding the new update available when you login to you system and start firefox. In this way it will handle the change to the latest version for you. Else you can uninstall the present version and install the new version downloaded form http://www.mozilla.com/en-US/firefox/. Mozila 3.0.1 is the latest.
You probably haven't updated your Firefox version. Check Menu Bar > Help > About Firefox to check the version. Firefox 3.5 is the version that offers HTML5 Video support. You can get the latest version at http:/getfirefox.com
The newest version of Firefox now (18th September 2011) is 6.0.2, for Winows. I'm not sure about Mac and Linux. Checkout on www.mozillafirefox.com
Microsoft has a download center where the latest version of Internet Explorer can be downloaded. Google Chrome and Mozilla Firefox are other well-known internet browsers.
Language packs are generally free (for example the latest version of Firefox has some).
It is Mozilla Firefox 3.5.2, I actually JUST downloaded it like a minute ago!
In the latest version of Firefox (3.5), go to Tools > Options > Main Tab > and under "Downloads", uncheck the box labeled "Show the Downloads window when downloading a file", click ok.
If you're using the latest version of Fedora (Fedora 12), Firefox 3.5 comes pre-installed on your system, and it is kept up-to-date automatically via yum/packageKit. However, if you have an older version of Fedora, or you want to get a more bleeding-edge version of Firefox (sometimes the updates lag behind a few days or you want the development version), you can compile it from source. Instructions can found in the link below.