Windows Phone 7 Series (hereafter I'll just call it WP7) debuted a while ago at a press event but it's true coming out party was this past week at MIX 2010. This conference is a designer-developer hybrid conference and, of all the Microsoft development conferences I've ever attended, this has consistently been the most informative and exciting of the bunch.

In case you've been hiding under a rock this past week, Microsoft has been showing off WP7 and the development experience for it. I'm going to oversimplify here, but this is the basic idea: You can choose to either develop for the platform in Silverlight or you can use the XNA toolkit normally used for building XBox and PC games in C#. WP7 has all the trimmings including push notifications, rich GUI (hardware accelerated), rich audio, the full power of Silverlight's media control, and it even has Xbox live integration allowing you to unlock achievements by playing games on the phone. Development tool is standard Visual Studio and for the Silverlight model you can use Expression Blend 4 to build you GUI (and there are some fantastic new improvements in Blend 4).

I'm going to talk mostly about the Silverlight experience here since the last time I used XNA it was in beta and XNA has come a long way since then and I couldn't possibly do it justice. Your application is made of up pages (this concept should be familiar to SL3 developers), with each page acting like a specialized SL user control. These pages can have an application bar, which is similar to an iPhone tab bar control. The difference is that when you tap the elipsis ("...") on the WP7 app bar, the app bar expands without you losing context while the iPhone tab bar "more" button transitions you to a fairly bland table view controller. At this point you can do pretty much anything you would normally be able to do in Silverlight, but you also get things like raw access to audio from the microphone, pickers for all native types of data on the phone like contacts, etc and the ability to send e-mails and SMS - all the stuff you'd expect to have.

So, how does it feel to code for this thing and, more importantly, how does it compare to writing iPhone apps? First, let me preface this by saying that I've been writing iPhone apps off and on since before the SDK came out and we had to "fake it" with clever CSS and HTML and for the past few months I've been seriously writing heavy duty iPhone apps for real businesses. On many occasions over the past few months, I've said that developing for the iPhone was 'fun' and 'what coding should be like'. That said, I have also forcibly rammed my head into my desk out of frustration with certain aspects of the iPhone development process.

Writing apps that look and feel like iPhone apps that look just like every other iPhone application is a task that takes little to no effort. I can go from empty project to a data-driven table view controller on the iPhone in pretty much no time at all. I can also do the same thing on the WP7 tools in about the same amount of time. Where the two begin to diverge is when I want to start customizing. I won't go into painful detail here because I plan on making a bunch of blog posts about WP7 and comparing it to the iPhone later. There are a few points that I want to make, however:

Push Notifications

As I said, I plan on delving into individual topics as I blog more about this, but I wanted to bring this up specifically. Dealing with the App Store and with the Developer Portal in general on the iPhone is a headache at best. When you add into it the juggling, management, and eventual botching of certificates and provisioning profiles, the mess gets even worse. Now you add into it the debacle of getting certificates based on provisioning profiles that are used by your servers to send push notifications to registered iPhone devices and it can bring the strongest of men to weeping on his knees. From firsthand experience, the act of getting your first push notification to work on an iPhone/iPod touch application is akin to climbing mount everest and when you get to the top you're thinking, "#@*! I have to do this again!?" With Apple, the phone contacts Apple to get a notification token (assuming the application is using a provisioning profile configured for notifications), the token then has to be sent by the app's code to the app owner's server for storage. That server needs to be configured with the right certificates to that it can send a proprietary binary package of goo containing the notification to Apple's servers, which will eventually make its way down to your app. Trust me, getting this to work is a victorious moment, preceded by weeks of eye-gouging pain.

Here's how it works with WP7: App gets a unique notification URI that represents notifications for that app on that device. App sends the URI to the app owner's server. When you want to send a notification, HTTP POST the contents of that notification (XML payload) to Microsoft's notification server. That's it. Done.

Small side note here: I like that you can send unobtrusive toasts with WP7 far better than sending modal dialog boxes with iPhone, they feel more like the Palm Pre notifications than iPhone dialogs. There are no certificates and private keys to manage, there are no provisioning profiles to deal with, there are no certificates required to be present on the notification sending server and there is no management portal you have to go to in order to maintain this stuff. For the first time recent history, Microsoft took the "it just works" approach whereas Apple's is hideously and unnecessarily complex.

GUI Customization

I alluded to this earlier in the post. If what I want to do is display two rows of textual information in a table view cell, then the iPhone gives me that out of the box and my application will feel perfectly at home on the device. However, when I want to mix in some icons and some other gauges and indicators that might not fall into the existing line-up of controls, I quickly drop from feeling safe and secure to feeling like I'm back in the low-level Windows programming days of yore where everything I do needs to be a custom view with a custom render/paint method. It gets tedious, difficult, and time-consuming FAST.

Because WP7 lets me do all this stuff in Silverlight, I can use the advanced, composited, declarative UI to do truly remarkable things in very little time at all. I could make the cells in my table view (list view or grid in SL) have three rows and put whatever controls I want in there. Creating a type of UI that doesn't exist in the stock toolbox in Silverlight is easy... doing the same in the iPhone feels positively primitive by comparison.

Overall Experience

As you'll see in the blog posts I'm planning on doing, WP7 development is like a  breath of fresh air. It's funny, because I remember saying that when I first got my hands on the iPhone SDK and I was comparing iPhone development to Compact Framework for Windows Mobile. Cast aside all your preconceived notions about all previous versions of Microsoft mobile OS development - this is something entirely new. Also, keep in mind that when you build your mobile app in Silverlight, if you do it with a little forethought, you could potentially share 90+% of your code for an app that works on WP7, on a PC, and on a Mac.

I will still build apps for the iPhone, but only because people continue to want to pay me to do so. From now on, my mobile development for pleasure is going to be entirely WP7 based.