I have spent a lot of time researching cross-platform options for mobile development lately. As of Summer 2009, this is a bewildering space undergoing rapid change. InfoWorld put out an article six months ago comparing mobile platforms from a developer’s perspective: Developer’s Eye View of Smartphone Platforms. (It is good to see that venerable publication still putting out good info — I grew up reading it in the late 80s.) In 13 pages it just scratches the surface of how the platforms differ for developers. Six months is a long time. Since that article came out, Apple released the 3.0 iPhone SDK, launched the long awaited Apple Push Notification, Palm launched the PalmPre and we all probably know an alphageek who picked up an Android phone.

In the midst of all this, several projects have attempted to deliver open source, cross-platform mobile development frameworks — mostly by packaging up some form of HTML and Javascript programming with varying access to the specific capabilities of the various devices and platforms. The must-support platform is of course Apple’s iPhone. However, there are gotchas. Apple appears to forbid implicitly or explicitly the use of 3rd party libraries. Who can say whether that might include for instance the popular, iPhone on Rails library? What is the difference between that and what PhoneGap provides? How about the new Appcelerator ? Or Rhomobile, which even promises to let us write apps in our beloved Ruby!? (albeit compiled and not interpreted) Some developers using the PhoneGap are known to have experienced problems while others have had their apps approved. The criteria are unclear.

Open source libraries such as these have advanced the state of the art. In many ways, they are the state of the art. Many of the most creative developers rely on open source and there is no doubt it has helped to keep domestic software development competitive. Much of the boom in web-based software and social networking was made possible by advances in and increased adoption of open source frameworks. The economics of software dictate that as developer productivity increases, whole new classes of applications become economically viable. We are on the cusp of being able to develop custom mobile applications for business at a cost and complexity similar to the custom web applications we develop today.

Over the last six months, the iPhone has further consolidated its market leadership leading to stellar financial results for Apple. The number of applications available has ballooned into the tens of thousands but a quick perusal of the AppStore on iTunes reveals a lack of serious business apps. While enterprise developers have largely been stuck on the decidedly duller BlackBerry and Windows Mobile devices, more adventurous Enterprise customers have lately been salivating over the iPhone. Will iPhone win over a segment of the corporate market? And if so, will an enterprise development model friendly to smaller software vendors play a role? Will we be able to use open source frameworks like those mentioned? Time will tell.