JavaScript Scripting engine

Microsoft's Active Scripting technology supports JScript as a scripting language.
The Java programming language, in version SE 6 (JDK 1.6), introduced the javax.script package, including a JavaScript implementation based on Mozilla Rhino. Thus, Java applications can host scripts that access the application's variables and objects, much like web browsers host scripts that access the browser's Document Object Model (DOM) for a webpage.
The Qt C++ toolkit includes a QtScript module to interpret JavaScript, analogous to Java's javax.script package.
JSDB (JavaScript for Databases) is an open-source JavaScript shell for Windows, Mac OS X, Linux, and Unix, which extends the Mozilla JavaScript engine with file, database, email, and network objects.
jslibs is an open-source JavaScript shell for Windows and Linux which extends the Mozilla JavaScript engine. It has the ability to call functions in commonly used libraries like NSPR, SQLite, libTomCrypt, OpenGL, OpenAL, and librsvg.
Late Night Software's JavaScript OSA (aka JavaScript for OSA, or JSOSA) is a freeware alternative to AppleScript for Mac OS X. It is based on the Mozilla 1.5 JavaScript implementation, with the addition of a MacOS object for interaction with the operating system and third-party applications.