Smart Clients

About four years ago I heard about Smart Clients. Back then this term had particular meaning. Application can be considered Smart Client applications if

• It's a desktop application with rich user interface.
• As desktop application, it can work in disconnected mode.
• When connected, additional functionality may be available.

I thought that it was a great idea and truly believed that such kinds of application would become highly popular. Instead, what we can see is an unprecedented rise of web applications.

I still like all these ideas, and still think that the idea of smart client application is valid. But it worth to analyze what went wrong with them, and why web became so popular. Well, analysis may be a too strong word, just some thought.

One of the reasons, I believe, is that it's much easier to develop web application than occasionally connected desktop application. There are so many people involved in web development now, that the choice of technologies, frameworks and examples is huge. In result, there is a new generation of developers who never developed anything by web applications. And these process feeds itself, the more popular web development is, the easier it becomes.

Another reason is that desktop applications were not that good looking. Somehow web became more visually appealing. Why did it happen? For one thing, desktop application development stuck with Win32 windows. (I have to mention that my view are based on my experience, which is development for Windows OS). As much as I love .NET, all we had for user interface were WinForms, and this is just the wrapper around old Win32 windows, where presentation cannot be easily separated from development, by which I mean coding. It's different in Web. HTML, with it's styles, allowed to developers to develop, and designers to design. And these are different talents.

Finally, it appears that many applications just don't need neither rich UI nor ability to work being disconnected. There is just no benefits for them in that.

So, where do we go now? Is it time to bury the idea? After all, even the term Smart Client is deluded. Every desktop application can be named Smart Client today, and I even heard the term applied to a web application with Java applet as a client, that just cannot work disconnected at all. I would argue that we should not just write it off yet. Here is why.

Trends. Let's look at where web applications are going. Many of them remind desktop applications now. Not only very rich UI is available through JavaScript, Flash, or Silverlihgt, but because they are starting to store their data on a client machine. Just look at such things as Google Gears, or Isolated Storage in Silverlight, I am sure there are others.

WPF gives desktop developers what web developers had long time ago. Presentation is finally separated from implementation. Layout of application is not part of the code anymore. With tools like Expression Blend designer can do his job while developer does his. And the results can finally be better than what they are in Web. There are concerns here. After all, WPF is not exactly new already, and adaptation is not going really fast. I would suggest that one of the reason is that XAML is too complicated, another is there are no tools on the market that could much those available for web designers. Expression Blend is definitely not there yet. Hopefully, the latter is just the matter of time, and once those tools are available, the complexity of the XAML will be hidden from designers.

Bottom line, I am optimistic about Smart Client applications. The deployment can be simplified with technologies like ClickOnes, or similar. Automatic updates are already a must. Disconnected mode is not that critical now, but having local cache is easier to do with existing light weight databases. WPF will bring pretty look. Sure, there are so many applications that just belong to web, there are those that can be better with smart clients, particulary business applications (emails, data entry applications, any office application).