NoScript notifies you about blocked script tags (<script>) and other active content using a standard "Popup blocker" style messages (you can easily customize or disable it).
You can customize almost everything in the appearance of NoScript.
Embedding options allow you to block Java, Flash, Silverlight, and other plugins, as well as page elements such as audio or video tags, IFRAMEs, FRAMEs, fonts, and WebGL.
You can also use external filters such as Blitzableiter to sanitise active content.
You can set extra restrictions for untrusted sites, like preventing automatic page refreshes and redirections. You may want also to enable rich-text clipboard operations on trusted sites (e.g. your web mail "compose" page).
NoScript supports the Strict Transport Security standard, helping to ensure that all communication with sensitive sites is encrypted. It can also force sites to use HTTPS connections and secure cookies.