Native Client (NaCl)

Native Client is a sandbox for running compiled C and C++ code in the browser efficiently and securely, independent of the user's operating system. Portable Native Client extends that technology with architecture independence, letting developers compile their code once to run in any website and on any architecture.

In short, Native Client brings the performance and low-level control of native code to modern web browsers, without sacrificing the security and portability of the web.

Getting started tutorial:

• Part 1: Simple NaCl Web App -  shows how to build and run a web application using Portable Native Client (PNaCl). This is a client-side application that uses HTML, JavaScript and a Native Client module written in C++. 
• Part 2: SDK Build System and Chrome Apps - shows how to convert the finished PNaCl web application from Part 1 to use the Native Client SDK build system and common JavaScript files.

Native Code on the web: Portable Native Client

Portable Native Client is a technology that enables portable, secure execution of native applications in Chrome. Developers produce a platform-independent form of their native application. Chrome translates this form to run on the user's device at better than 80% of native performance.