So, Flash is a vibrant platform that offers a high degree of rich functionality, some of it best-of-breed. Sites and applications developed with Flash are available to virtually every non-mobile Web user, and likely to be available for most mobile users before long, except for those using Apple products.
HTML5 is an exciting, evolving Web coding language with extensive support from all of the Internet's heavy hitters – Google, Apple, Microsoft (albeit slowly), Mozilla, Opera, and yes, even Adobe. It promises to simplify and speed-up both the Web development and Web browsing experience, has native capability to handle multimedia and rich Internet functionality without external plugins, and has ambitions to be the technology that finally bridges all devices, mobile included.
A number of leading Internet voices argue that it's not an either-or scenario. Flash is the best platform for some applications, and HTML5 for others. But how is a developer to decide what the best technology is for the project that's in front of them? Assuming A) that the technology can perform the desired function and B) that the end product is available on user devices, it gets down to a matter of performance.
See HTML5 run
Because it's an open technology (with the possible exception of video), HTML5 promises to lend itself to the robust performance monitoring, measurement, and diagnosis that's been available for other open Web technologies. And it is expected that the advances found in HTML5 will, if used judiciously, be a boon to overall page performance.
One of the most anticipated features of HTML5 – and one of the most debated – is the ability to handle audio and video natively in the browser. A few simple lines of code is all it takes to embed A / V files, and, once browsers are updated to handle HTML5, the user would need no special plug-ins to run the files.
As mentioned above, Flash is by far the dominant force in online video. But HTML5 is already making inroads. Vimeo has introduced HTML5 video capability in a new universal player, enabling its videos to be viewed on mobile devices, including those from Apple. And Google has introduced a new, HTML5 mobile version of its site, m.youtube.com, which is promoted as delivering better video with a better interface than Apple's own YouTube app.