Google has officially launched Native Client – a means of securely running C and C++ code inside a browser – as part of a new stable version of its Chrome browser that activates this rather controversial sandboxing technology.
Mountain View turned on Native Client, aka NaCl, in the Chrome beta last month, and on Friday, it debuted in the new Chrome 14, a stable release that also includes Google's new Web Audio API.
In essence, Native Client is a sandbox designed to securely run native code. With the 32-bit x86 instruction set, Native Client taps the hardware's rarely-used "segment registers" to restrict where a program can read and write data in memory and to make sure the program doesn't jump to code outside a certain memory range. Plus, it uses a modified compiler and a code verifier that restrict code jumps.
So, yes, apps must be ported to the platform.
"Once you download the native code, there's no opportunity for browser optimization. There's no opportunity for all kinds of things. You have to keep in mind that the evolution of browsers over the last several years has been that we have made a 10X improvement on existing sites. The evolution of browsers has made everyone's applications faster, whether or not you've updated that site in X number of years.
"With Native Client, all of that disappears. The fast innovation we've seen on the web disappears. A source code–based world means that we can optimize things that the user hasn't even thought of, and we can deliver that into their hands without you, the developer, doing anything."
At the moment, Native Client is only available for use with 32-bit and 64-bit x86 chips, but the company is working on a portable version known as Portable Native Client, aka PNaCl (pronounced "pinnacle"). Rather than generate x86, PNaCl will translate native code into bitcode using a compiler based on the open source LLVM (low-level virtual machine) project. When the browser downloads this bitcode, it will then translate it to machine code and validate it much like Native Client does today.
Because PNaCl is not yet in place, Google is only allowing Chrome 14 to run Native Client applications that come through the Chrome Web Store. This way, the company can ensure that developers offering versions of their applications that run on all available platforms – i.e. 32-bit and 64-bit x86.
Chrome 14 for Mac also includes a few changes specific to OS X Lion. It uses Lion's "overlay scrollbars", which only appear when you're scrolling, and it includes "initial support" for full-screen mode. You can switch to full screen using the Ctrl+Shift+F key combination or the Mac's full screen key.
You can download the release here. If you're already running Chrome, your browser will automatically be updated to the new version. ®