*[http://bugzilla.mozilla.org/show_bug.cgi?id=608741 Type Inference]: perform hybrid dynamic/static analysis of JavaScript code to provide better type/invariant information to the JIT compiler
*[[Javascript:SpiderMonkey:BaselineCompiler|Baseline Compiler]]: New Baseline JIT to replace Interperter+JM.
*[https://bugzilla.mozilla.org/show_bug.cgi?id=650180 [IonMonkey|IonMonkey]]: upgrade current JIT compiler with classic SSA-based compiler techniques to allow better optimization of JIT code
*[[JavaScript:SpiderMonkey:RegExp API|Expose ECMA 262 Regular Expression API]] to C/C++ clients.
*A [[JavaScript:SpiderMonkey:Parser API|new SpiderMonkey API]] for building and inspecting parse trees.