Currently, V8 does not have an interpreter. Instead, initial execution JavaScript code is first parsed and compiled into an unoptimized state. Because of the way the parser and compilers work together, some code is later parsed two or even three times. In all Google says that V8 spends 33% of a page’s startup time parsing and compiling code. This also results in significant memory cost. By using an interpreter, Google hopes to reduce the memory usage of the current system. Ignition still relies on a parser, but the JavaScript is compiled to bytecodes rather than native code. Continue reading this story here.