What should be the platform of your next application?

I'm currently thinking about the next steps for my information manager Hyena. It exists in two versions, as an Eclipse plugin and as a GWT-based web application. Having to maintain two versions is a major burden, so I've been thinking: What would would be the ideal platform on which to base one's application?

My wishes for such a platform are as follows:

• Simple deployment: Nothing beats pure webapps in this regard. Having a webapp available everywhere is cool, too.


• Extensibility: For larger applications, if you want someone to code new functionality, doing it as a plugin is very elegant.


• Development tools: With inadequate tools, implementing and maintaining an application becomes much more work. It should be easy to find one's way around a platform and source code should be easy to change and navigate.
  
  

Technology-wise, times have never been better for developers. A lot of exciting stuff is available, for free:

• Eclipse: I love its GUI (which is remarkably clean considering how much functionality it has), but am not too fond of its innards. They always felt harder to understand than necessary, slightly overengineered, and include anti-patterns that make it difficult to discover things (see “Eclipse 4 wishes: simplification first, then innovation”). I'm also not sure that the pride of amassing frameworks serves Eclipse well. This leads to design by committee, instead of a single tight overarching vision. Lastly, Eclipse seems to pin its hopes for web enabledness on RAP (or something like it). What I've seen so far of RAP did not instill confidence: It is slow, its UI awkward, and it will never work in offline mode.
  
  


• OSGi: Very useful and powerful if you need extensible software. Still a bit complex but that will hopefully change as it finds its way into the Java language.
  
  


• GWT: I was long very sceptical and wrote my own JavaScript, but now I am a convert, because having a single language and the power of the Java tools leads to a lot of productivity. Even though writing GUIs with GWT is almost as simple as with, say, Java Swing, one problem remains: layout. Many things that are easy in Swing or SWT are difficult or impossible in a browser.


• DWR: Nicely done. But I've tried it (together with Dojo) and maintaining two code bases (client + server) is not much fun. Plus, JavaScript development tools are not yet at the level of the Java tooling.


• Appcelerator: Intriguing option for turning a web application into a desktop application. I'm not sure coding the UI and the application in two different, usually not well integrated languages works. Thus, I can imagine using it with GWT or with JavaScript.


• Trephine: Brings desktop features such as the clipboard or file system access to web applications via a small signed Java applet.
  
  


• Bespin: Ajax application that draws its own UI via the canvas API (see picture below). Very impressive and indicative of web browsers soon being superior deployment platforms. I would also assume that by being canvas-based, rendering and UI differences between browsers are less of an issue.
  
  

So where does that leave one when writing the next application that should be web-deployable? I see the following options:

• GWT plus
  
  


• canvas-based browser UI: would be a perfect solution for me (see “Project Bespin and the Future of Web UI According to Google”).


• GWT + XUL: would be Firefox-only, but still kind of cool. Last I checked, there was nothing usable out there apart from a few experiments.


• Running GWT on OSGi could deliver extensibility, but I'm not sure how well the client side could be extended, since GWT cannot currently dynamically instantiate classes. GWT.create() only works statically. That means that plugins cannot contribute code to the client side of a GWT application.
  
  


• Pure JavaScript: That is client-side JavaScript and server-side JavaScript. Currently, neither language nor tools nor (non-canvas) browser-based UIs are there yet. But they probably will be eventually.


• Applets, Flex, Silverlight: either don't integrate well with web browsers or have inadequate development tools or don't integrate well with web servers (meaning that it is useful if server and client can share data structures easily, having to define the same class and/or tool functions twice is unnecessary overhead).

Other inspiring technologies that are interesting, but not (yet) relevant for me:

• Newspeak: Takes discoverability and clean but powerful language design to a whole new level.
  
  


• Lively Kernel: Sun Lab's go at a pure JavaScript runtime environment. Still feels a bit strange to use and I'm not sure about their server story. But a cool project none the less.


• Mobile webapps: When it comes to mobile devices, the predominant browser is Webkit, so it is really easy to write cross-platform applications as webapps there. Google leads the way via its mobile versions of GMail and GCal.

Am I missing something? Did I misjudge some of the technologies?



Related reading:

• Running a WAR as a desktop application.