One of the key features of the web is that it’s pretty safe to click on almost any link. Your browser can fetch code from some unknown server on the internet and run it.
In the browser you can use any language you want – as long as it’s JavaScript. JavaScript is an interpreted, dynamically-typed language, and it was specifically designed to protect netizens from malicious and buggy code. Nowadays you can also program with other languages and convert the result to JavaScript with suitable tools (Java, C/C++, etc..). With browser extensions some more languages are possible (Java, Flash actionscript etc..).
Native Client – a Google open source project more than three years in the making – is specifically designed to run native code securely inside web browsers. It tried to put web applications on “the same playing field” as local applications, providing the raw speed needed to compete with traditional software on 3D games, video editing, and more. Google Native Client: The web of the future – or the past? article gives some more details on this technology. Google’s idea is to create a system that tries to give languages like C and C++ – but eventually others as well – the same excellent level of portability and safety that JavaScript provides on the web today.
As it stands today, Native Client is a software “sandbox” meant to securely run native code inside a browser. Native Client can give you a tremendous improvement in performance compared to other options for running code in the browser. The rub is that Native Client isn’t the web – at least not yet. It will soon be an integral part of Google’s browser and its browser-based operating system.
Chrome will only accept Native Client applications distributed through the Chrome Web Store, and Google will only allow Native Client apps into the store if they’re available for both 32-bit x86 and 64-bit x86 (the ARM version of Native Client is not yet ready for prime time).
The problem for wide adoption is that Native Client hasn’t been integrated with other browsers. It hasn’t been standardized. Is this development direction good or bad for the web I am not sure.
This interesting outgrowth of Google’s Native Client: a Google engineer has ported MAME 0.143 to the browser-based platform, and written about the process in detail, outlining the overall strategy employed as well as specific problems that MAME presented.
“The port of MAME was relatively challenging; combined with figuring out how to port SDL-based games and load resources in Native Client, the overall effort took us about 4 days to complete.”
Case Study: Porting MAME to Native Client
https://developers.google.com/native-client/community/porting/MAME
I saw this information first at http://games.slashdot.org/story/12/01/01/0148246/mame-running-in-chrome