Stylish 0.1.1 has been released. Stylish allows you to easily manage stylesheets that affect the look of websites and of the user interface. Supported versions: 1.4 (1.5 beta1) to 1.6a1 (trunk nightlies).
Download here
User interface
* Options/Preferences under the Extensions menu will give you the management dialog.
* Highlighting text will give you a context menu option, "Add Selection To Stylish..."
* CSS files will give you a context menu option, "Add File to Stylish..."
* Several styles are included by default (but disabled).
* The rest is self-explanatory
* Available in en-US, fr, it, es-ES, and nl-NL.
How is this better than editing userContent.css and userChrome.css?
* Takes effect almost immediately (on next page load for websites and on next window open for UI) instead of requiring a restart.
* Don't have to find your profile folder.
* Organization - you enter a description for each style instead of having them all clumped together.
* Easy to enable and disable individual styles.
* Syntax errors in an entry will not bork all subsequent entries.
Tips for writing your own styles
* Unlike userChrome.css and userContent.css, styles affect both chrome and content. If you want something to only apply to chrome, make XUL the default namespace (see default styles for examples of this). If you want something to only apply to content, use -moz-document selectors or use a descendant selector (ex: "html #ad" instead of "#ad").
* If you don't know already,
-moz-document selectors are cool. They allow you to write styles that only apply to certain pages, servers, or domains instead of having to use wacky selectors to make a style apply to only one page.
Known issues
* If you delete all the styles, you can't add a new one without restarting Firefox.
* Deleting a style will hide all styles below it in the manage dialog. They reappear when the dialog is closed and reopened.
* Styles are not validated before they are added.
* Styles are not sortable
Possible future features
* If the first line of a style is comments, that should become the description of the style.
* Import userChrome.css and userContent.css
* Link to style repository