Firefox 4 Beta 2 is now officially my new browser since I'm able to run Firebug, Greasemonkey and Stylish.
You can download the extension from the following locations:
- Greasemonkey 0.8.20100408.6.3 Mod FX4 [http://space.geocities.jp/alice0775/REQUEST/greasemonkey-0.8.20100408.6.3-mod-fx4.xpi]
- Stylish 1.0.11 [http://userstyles.org/apps/Stylish-1.0.11.xpi]
- Firebug 1.6a18 [http://getfirebug.com/firstrun]
Want to thank Bseos for sharing the links for Greasemonkey and Stylish