c69's Browser Pit

As well as the modern technologies built into the browser, we use various parts of CommonJS including Promises, Modules, and package.json. We also take advantage of Node.JS.

The main aim of Montage is to help developers be able to develop native quality applications using web technologies, as quickly and easily as possible. As such we support components using HTML5 templates, Two way data binding (to both objects and components) , serialization, extended event handling, an optimised component draw cycle (for efficiently repainting when updating the DOM), keyboard shortcut handling, gestures and composers, data converters, and much more.

Unlike in other browsers, Chakra’s just-in-time (JIT) compiler runs on a separate dedicated thread and thus does not interfere with script execution.

To further reduce the time to first executed instruction, Chakra processes and emits bytecode only for functions that are about to be executed using a mechanism called deferred parsing.

We enhanced Chakra’s interpreter to collect it at runtime, a technique we call dynamic profiling. When a function is scheduled for JIT compilation, the compiler examines the runtime profile gathered by the interpreter and emits code tailored to the expected inputs.

...
The interpreter gathers information for the runs it observes, but it’s possible that the execution of the program will lead to runtime values which violate assumptions made in the generated optimized code. For every assumption it makes, the compiler emits a runtime check. If a later execution results in an unexpected value, the check fails, execution bails out of the specialized machine code, and is continued in the interpreter. The reason for bailout (the failed check) is recorded, additional profile information is collected by the interpreter, and the function is recompiled with different assumptions. Bailout and re-compilation are two fundamentally new capabilities in IE10.