Google native code browser plug-in gets tickled

The Tcl scripting language has been plugged into Google's Native Client, allowing Tcl code to run inside the Google Chrome browser in much the same way that JavaScript does.

Using Native Client – a Google-created plug-in for securely running native code inside the browser – Tcl now has direct access to the Chrome DOM. "The net effect for the Tcl developer is that now he can read and write to the DOM, and be notified of GUI or network events, just like any JavaScript programmer," developer Alexandre Ferrieux tells The Register. "And like for JavaScript, this happens on the client side, which is a game-changer for us Tclers, who are accustomed to being trapped on the server side. [You get] interactive speed regardless of the connectivity."

Ferrieux, the man who moved the language to Native Client, provides a demonstration of Tcl directly accessing the HTML5 canvas element.

Some have claimed that this is the first scripting language running on Native Client, but other languages have made the move as well, including OCaml and Lua. But this is the first language that fits so nicely with Google's wonderfully geeky naming conventions. Some have called this NaTcl. From sodium chloride to, well, sodium tetrachloride.

In February, Google released the first official version of the Native Client SDK. Native Client is designed to speed the performance of web applications, allowing apps coded in, say, C or C++ to be securely transferred over the web and executed inside the browser. The idea is to work around the speed limitations of JavaScript.

"While the [Chrome] team has made JavaScript tremendously faster over the last two years, there's a lot of applications out there that have existing audiences that are [written in native code, such as C and C++], and there are a few that are specialized applications that need every last bit of performance the hardware can offer," Google engineering director Linus Upson told us in December. "Native Client is a way of addressing both those issues."

At one point, Google built a Native Client compiler for Go, its New Age programming language that provides extreme concurrency while running at speeds similar to C. But Go co-creator Rob Pike tells us that the Native Client Go work is now on hold, due to the rapid changes the Native Client team were making to the plug-in.

Originally developed in the late '80s at the University of California Berkeley as the Tool Command Language, Tcl is essentially a scrubbed and enhanced Unix shell. "It dwells in the same area as Lisp and Scheme, in that it has an extremely simple and regular syntax, with next to zero reserved keywords, very few special characters, and a very simple semantics based on a never-violated principle: 'Everything Is a String'," Ferrieux says. "That allows humans to reason about programs with certainty without any knowledge of the implementation details."

Now that Tcl – pronounced "tickle" – is up and running on Native Client, Ferrieux intends to move the accompanying Tk graphical user interface tool kit to the platform as well. "Another important thing from the standpoint of a Tcler with a Tk background, is that thanks to the exquisite flexibility of the language, there's very little more to learn [to make the switch to Native Client]," he says. "Indeed, the complete emulation of Tk's most useful idioms at a syntactic level is possible, and will be completed shortly."

Well, you do have to learn your HTML5. ®