| Chakra | |
|---|---|
| Developer | Microsoft |
| Initial release | 2009; 17 years ago (2009) |
| Written in | C++ |
| Operating system | Microsoft Windows |
| Type | JScript engine |
| License | Proprietary |
Chakra is aJScript engine used in theInternet Explorerweb browser, both developed byMicrosoft asproprietary software.
Microsoft later developed a newJavaScript engine for itsMicrosoft Edge Legacy browser, which is confusingly also namedChakra.Microsoft Edge changed toV8 (JavaScript engine) in 2020.
A distinctive feature of the engine is that itjust-in-time (JIT) compiles scripts on a separatecentral processing unit (CPU) core, parallel to the web browser.[1][2] Though Microsoft has in the past pointed out that other elements, such asrendering andmarshalling, are just as important for a browser's overall performance,[3] their improvements to the engine were in response to evolving competing browsers, compared to which IE8 was lagging behind in terms of client-side script processing speed.[4]
SunSpider tests performed on November 18, 2009 showed theProfessional Developers Conference (PDC) version of IE9 executing scripts much faster than IE8, but slower thanFirefox 3.6,Chrome 4, andWebKit Nightly.[3] The same test performed on March 15, 2010 showed the first IE9 Platform Preview (using the then-current version of Chakra) to be faster than Firefox (withSpiderMonkey), but slower thanSafari (withSquirrelFish Extreme), Chrome (withV8), andOpera (withCarakan).
On March 8, 2011, Microsoft published results showing the32-bit Internet Explorer 9 to be faster than Safari, Firefox (withTraceMonkey), Chrome, and Opera.[5]
March 2011 performance tests forZDNET concluded that Internet Explorer 9 (32-bit),Chrome 10, andFirefox 4release candidate were "pretty evenly matched."[6]
In 2012, subsequent versions of Chakra, such as the version included inInternet Explorer 10, introduced additional performance changes, including JIT compiling onx86-64 andARM architectures, and optimizations related tofloating point math andgarbage collection.[7]