Firefox tab close button on all tabs

Visibility of tab's close button can be set by modifying browser.tabs.closeButtons through about:config. The values are:

// Where to show tab close buttons:
// 0  on active tab only
// 1  on all tabs until tabClipWidth is reached, then active tab only
// 2  no close buttons at all
// 3  at the end of the tabstrip

The problem is, that when browser.tabs.closeButtons is set to 1 the close button visibility depends on the opened tab number. If there are more tabs than the tabbar can show it goes into overflow mode and thus the tab close buttons are gone. This can be fixed by adding a few lines to your userChrome.css:

.tab-close-button { display: -moz-box !important; }
.tabbrowser-tab[pinned] .tab-close-button { display: none !important; } /* hide close buttons on app (pinned) tabs */

Hide native element inspector in Firefox 13+

I don't know why but Mozilla decided to not allow Firefox users to disable their native element inspector. It really gets in the way if you are using Firebug. Fortunately, Firebug allows us to hide it in the about:config page. Just change this value to false:

extensions.firebug.hideDefaultInspector

Synchronize NoScript with Firefox Sync

To enable NoScript synchronization via Firefox Sync go to about:config (type this in URL bar) and change noscript.sync.enabled to true.

Make NoScript permission toggle permanent

This also works if you've set 'Left clicking on NoScript toolbar button toggles permissions...'

CTRL + SHIFT + \ (backslash) toggles allowance status for the current top-level site temporarily by default, to make it permanent set the about:config noscript.toggle.temp preference to false.