The Sencha blog has a great series of posts on HTML5 support on various devices. This is of direct interest to Sencha because its products are JavaScript and CSS application frameworks, Sencha Touch for mobile and ExtJS for any browser. The latest post is on the Amazon Kindle Fire – and it is weak:
The Amazon Kindle Fire doesn’t seem designed to run HTML5 apps as a primary goal. It does a good job of displaying ordinary web pages and its resolution and rendering capabilities meet that need well. But there are too many sharp edges, performance issues, and missing HTML5 features for us to recommend that any developer create web apps primarily for the Kindle Fire. The iPad 2 running iOS 5 continues to be the tablet to beat, with the PlayBook a respectable runner-up in HTML5 capabilities.
Part of the problem is that the Fire runs Android 2.3.4 (Gingerbread) which has a weaker browser than later versions. That is not the only source of disappointment though. According to Sencha’s Michael Mullany, the GPU is not used for hardware acceleration of browser content, the JavaScript timer is laggy, there is no embedded HTML5 video (videos launch in a separate player), and CSS corners are not properly anti-aliased.
But what about the Kindle’s cloud-accelerated browsing that we heard so much about when it was announced? This is the biggest disappointment:
One of the main selling points of the Kindle browser is supposed to be its cloud-caching and pipelined HTTP connection that uses the SPDY protocol. This does seem to speed up normal page browsing a little, but it’s not very noticeable and we didn’t test this rigorously. But for HTML5 web apps, where code is downloaded and executed, there doesn’t seem to be any performance difference when we tested with acceleration on and off. It doesn’t appear as if client JavaScript is executed on the server-side at all, so the Kindle does not seem to have Opera Mini-style server-side execution. And SunSpider scores were essentially the same when accelerated browsing was turned on or off.
Moving on from Kindle, it is interesting but not surprising to see a great report for HTML5 in Apple’s iOS 5. Less expected though is a big thumbs-up for HTML5 in Microsoft’s IE10 preview on Windows 8:
Simply put, (and with the caveat that we were running on the notably overpowered developer preview hardware) the IE10 HTML5 experience is one of the best we’ve seen on any platform to date. After a decade of web neglect, Microsoft is back with a vengeance.
The main caveat is the absence of WebGL. Microsoft is supporting its own 3D graphics library.
Another worry for Microsoft is simply the level of hostility towards the company and IE in particular, among the developer and designer community it so much wants to reach. You can get a flavour of this from some of the comments to Mullany’s post, for example:
I never really like Windows and I absolutely despise Internet Explorer. There are so many exceptions in code to be made for Internet Explorer that i stopped trying so hard to make it look the same as other browsers. Hopefully, IE 10 will stop all of these exceptions and weird additions that are made to websites that make everything instantly awful so I can actually go back to trying to make things look nice in IE. It’s really sad though that so many people use Windows and IE that we cannot ditch it for a better system and better browser.
What about Android? The most recent offering covered in the Sencha series is Motorola Xoom which is a disaster:
We were excited about the first true Android operating system for tablets and had high hopes for a mobile browser that was as powerful as the platform. Sadly, the Xoom and Honeycomb are a real disappointment. We found consistent and reproducible issues in CSS3 Animations and CSS3 Transitions among other things. We had issues where the browser either hung or crashed. Regular scrolling was slow or below full framerate. We had issues where media playback failed or performed incorrectly. At times it felt like we were using a preproduction device, but we bought our test device from a Verizon Wireless store.
I have a hunch that the latest Galaxy Tab might fare better. Sencha did like the HTML5 support in the BlackBerry PlayBook though.
With Adobe Flash now in decline on mobile devices (Adobe is no longer working on the mobile Flash player) HTML5 support is all-important for rich browser-hosted apps; I will be watching with interest for future Sencha reports.