Wiktionary
scriptlet
n. (context computing English) A small script, especially a section of Java code embedded in (w: JavaServer Pages) code.
Wikipedia
Scriptlet
In JavaServer Pages (JSP) technology, a scriptlet is a piece of Java-code embedded in the HTML-like JSP code. The scriptlet is everything inside the <% %> tags. Between these the user can add any valid Scriptlet i.e. any valid Java Code.
In AppleScript, a scriptlet is a small script.
In Windows, a scriptlet is COM component including a HTML code and a script which may be written in a variety of scripting languages.