It is intended to be embedded in other applications that provide host environments for JavaScript. The most popular applications are Mozilla Firefox and the Mozilla Application Suite/SeaMonkey, along with Adobe Acrobat and Adobe Reader. SpiderMonkey is also the JavaScript engine for Yahoo! Widgets (formerly known as "Konfabulator") and UOX3, an Ultima Online server emulator. A rather popular and creative utilization of the SpiderMonkey JavaScript engine is the open sourceSphere suite of applications primarily intended to aid in the design of role-playing games. Parts of SpiderMonkey are used in the Wine project's Jscript (re-)implementation.[1]
TraceMonkey
Mozilla has added optimization using "Trace Trees" to SpiderMonkey. Due to be released in late 2008 or early 2009, Firefox 3.1 is slated to include this new optimization technique which offers "performance improvements ranging between 20 and 40 times faster in some cases"[2]
Malzilla - Tool for hunting malware by deobfuscating JavaScripts on web pages, using SpiderMonkey
TriXUL - (TriXUL CVS) - Trixul XML-based GUI toolkit embeds SpiderMonkey, using JavaScript to implement logic behind its GUI, supporting calls from JavaScript to C++ objects.