The firefox4-4.0-0.6.beta4 package install this new version besides the version 3.x. So you will have 2 entries in the Internet menu.

WARNING : a backup of your profile (~/.mozilla/firefox directory) seems mandatory.

Start by reading :

As always :

yum --enablerepo=remi install firefox4

No xulrunner update, this RPM provides his bundled Gecko engine.

Actually lot of extensions and themes are not compatible and will be disabled. For those I use:

  • Abblock Plus 1.2.2 : compatible
  • Add-on compatibility checker 0.6 : compatible
  • Dictionary switcher 1.0.1 : not compatible but works
  • DOM inspector 2.0.7 : compatible
  • Ecosia 1.0.5 : not compatible but works
  • Firebug 1.6X.0a20 : compatible
  • freerecord 3.4.2 : not compatible but works
  • Personas 1.5.3 : doesn't work
  • SQLite manager 0.6.0 : doesn't work
  • Web Developer 1.1.8 : not compatible but works

I continue to test the new features (Tab Candy and Sync) and I expect yours feedbacks.

A first SunSpider JavaScript Benchmark reveal a great performance improvement in 64bits.

Mozilla/5.0 (X11; Linux x86_64; rv:2.0b3) Gecko/20100815 Remi/fc13 Firefox/4.0b3
Total:                  748.4ms +/- 4.4%
Mozilla/5.0 (X11; U; Linux x86_64; fr; rv:1.9.2.8) Gecko/20100724 Remi/fc13 Firefox/3.6.8
Total:                 2029.2ms +/- 2.3%

For memory:

Mozilla/5.0 (X11; U; Linux x86_64; fr; rv:1.9.2b1) Gecko/20091106 Remi/fc12 Firefox/3.6b1
Total:                 2397.0ms +/- 3.0%
Mozilla/5.0 (X11; U; Linux x86_64; fr; rv:1.9.1.5) Gecko/20091105 Remi/fc12 Firefox/3.5.5
Total:                 3031.2ms +/- 1.5%

A second JavaScript performance test with V8 Benchmark Suite - version 5 confirm this result:

  • Firefox 3.6.8, score 225
  • Firefox 4.0b3, score 812