Apple rules the roost in tablets. Other platforms have tried to get into the market but without much success. Some such as Samsung are still here. Others like Palm arrived and disappeared in a blaze of fire-sale glory. None has threatened to overtake Apple's lead. Yet.
The announcement this month of the Microsoft Surface tablets is the most significant development in tablets since the 2010 launch of the iPad.
Not that the Surface has actually launched, merely announced. It has no price point and no launch date. Windows 8 isn't due to land until late summer but Microsoft clearly felt the need to make the big reveal now.
The timing of the event is sure to have had nothing whatsoever to do with the Google IO event where, to no little surprise, another tablet has been launched. Suddenly, everyone is a hardware manufacturer.
Google has now taken the wraps off the Nexus 7, a seven-inch tablet running Android. Although Google and Apple are now fierce competitors, the search giant may have Amazon's Kindle Fire in its sights rather than the iPad.
Two companies, which have focused in the past on developing software and working with hardware partners, have decided their hardware partners aren't up to the job.
This shift in itself is a triumph of sorts for Apple's philosophy of integrating software and hardware. Quite what Microsoft and Google's hardware partners do next, goodness knows.
The Google tablet is far less interesting than Microsoft's Surface devices. The Nexus 7 is just another Android tablet, and Android has so far failed to have the same traction in the tablet market as it has with smartphones. Presumably, the Nexus 7 will do the same job for tablets that the Nexus smartphone does - to demonstrate what Google accepts as a best-of-breed device.
Both companies have long relied more on licensing software to partners than delving into hardware. For Microsoft in particular, this approach has been the basis of its tremendous success. The Xbox has been a rare success; the Zune and Kin phones are considerably less celebrated.
The Surface tablet, while not a wholly unexpected route for Microsoft, would have been largely unthinkable a year or so. That Google, which also worked primarily with hardware partners, has made a similar leap demonstrates the powerful influence of the iPad.
And to think just a couple of years ago, Microsoft founder Bill Gates said of the iPad: "It's a nice reader, but there's nothing on the iPad I look at and say, 'Oh, I wish Microsoft had done it'."
Two years down the line and there's more than a striking similarity between the two devices but the Surface has some significant differences that proves it has Microsoft's tablet ideology running through it.
What makes the Surface so interesting is that it represents Microsoft's first shot at a post-iPad tablet. It has clearly inherited some of the features of the iPad but some of its DNA is shared with the vision Gates had over 10 years ago.
Microsoft was probably the first major technology company to push the tablet form factor some 10 years ago but without success. The major problem with the tablets running Windows were that they simply considered themselves another kind of PC rather than something else, as Apple did.
Jobs and his team rethought what the tablet experience should be without paying any respect to the prevailing wisdom. Given the relatively flat reception the iPad experienced, it was clear no one really got it at first.
In a 2010 interview with BNET, Gates said: "You know, I'm a big believer in touch and digital reading, but I still think that some mixture of voice, the pen and a real keyboard - in other words a netbook - will be the mainstream on that."
Looking back on the quote, it's easy to see that Gates' ideas remain embedded in the new devices. The Surface has a stylus and a genuinely innovative cover that turns into a keyboard when it's opened.
Windows 8's challenge to the iPad
For some time Windows 8 has interested and excited me. Not enough to buy a product but enough to think that it can do more to challenge the iPad than Android can or has so far.
The Surface is clearly a new approach and Windows 8 a new way of thinking about Microsoft's operating system. I can't but think that this fresh approach might attract a new breed of tablet user. New ideas will appeal to new demographics, in particular the corporate users so beloved of Microsoft.
The really interesting, and telling, comment from the Surface presentation came from Microsoft's Windows division president Steven Sinofsky. He described the Surface as a "tablet that's a great PC - a PC that's a great tablet".
Just as Apple strips away unnecessary layers and complexity to make something as simple as it can possibly be, Microsoft risks the opposite with this kind of philosophy.
Surging tablet sales vindicate Jobs
The success of the iPad has been in starting again. Steve Jobs famously defined the iPad and its iOS kin as "post-PC devices". The company viewed the term 'PC' as a legacy product and one which was slowly coming towards the end of its dominance as a computing platform. Now, with tablet sales surging and PC sales stagnating over multiple quarters, you've got to feel he had a point.
The iPad is on a clear and simple evolutionary path. Meanwhile, Microsoft is taking a different road, with the Surface almost like some kind of hybrid device. Microsoft is loath to abandon the PC platform or concept - CEO Steve Ballmer has made this point repeatedly.
The hybrid approach lets Microsoft appeal to existing users. On the other hand the company runs a serious risk of confusing them, developers, and itself with a muddled brand and product that lacks a clear sense of purpose or audience.
Just as with Android and other tablets - those that haven't been abandoned - Microsoft has clearly been tempted to define the Surface in areas where the iPad has been criticised, by adding ports, offering expandability, little stands and styli. These are all things that Apple deliberately shunned to deliver that it perceived to be a superior user experience.
The things that are left out are as important as the things that are included. The success of the iPad is testament to the fact that sometimes, less is more.