Appcelerator’s Titanium is an open-source development platform that allows developers to create native applications for both mobile and desktop use. What’s better? Titanium allows developers to code in JavaScript, HTML and CSS.Titanium takes your Javascript code, analyzes and preprocesses it and then pre-compiles it into a set of symbols that are resolved based on your applications uses of Titanium APIs. From this symbol hierarchy we can build a symbol dependency matrix that maps to the underlying Titanium library symbols to understand which APIs (and related dependencies, frameworks, etc) specifically your app needs. We are using the word symbol in a semi-generic way since it's a little different based on the language. In iPhone, the symbol maps to a true C symbol that ultimately maps to a compiled .o file that has been compiled for ARM/i386 architectures. For Java, well, it's more or less a .class file, etc. Once the front end can understand your dependency matrix, we then invoke the SDK compiler (i.e. GCC for iPhone, Java for Android) to then compile your application into the final native binary. So, a simple way to think about it is that your JS code is compiled almost one to one into the representative symbols in nativeland. There's still an interpreter running in interpreted mode otherwise things like dynamic code wouldn't work. However, its much faster, much more compact and it's about as close to pure native mapping as you can get.