Root Beer Float
Root Beer Float is a dark Notepad++ theme, based on the Obsidian theme.
Styles are defined for the web languages I usually work with: PHP, XML, HTML, CSS, SQL, Javascript. Other languages will just default to Obsidian styles.
To install, simply place the XML file into your Notepad++ installation folder, in the "themes" directory. Usually this will be something like c:\Program Files\Notepad++\themes.