How Facebook Mobile Was Designed to Write Once, Run Everywhere

Facebook has the most downloaded native application of all time. It also has perhaps the most visited mobile website of all time with nearly 350 million users and growing, using everything from basic feature phones to the smartest smartphones. It is available everywhere. The company started working on mobile solutions in 2006 and since then has grown with the times, using the tools available to them as they went along, from m.sites and WebKit touch interfaces to HTML5. Facebook's creed, really just a way to make their developers' lives easier, is to write once, run everywhere. This has been next to impossible.

Facebook mobile is predicated on browser technology. As Facebook's engineering manager Dave Fetterman says in the transcript below, the browser is what Facebook is good at, how it got where it is now and how it will iterate for the future of mobile. We will touch on the future tomorrow, but be sure to read Fetterman's presentation at Facebook's f8 developer conference below because it will inform what we are going to explore tomorrow morning. Really, how did Facebook design for all those platforms and devices?

What is below is a direct transcript with photos from Fetterman's f8 presentation. A few things to note:

Facebook mobile has its backbone in its mobile website. Everything that is built into the native applications actually comes from the mobile Web. Think of the way PhoneGap wraps a browser-based website and that is how Facebook approached the problem. And then some.

HTML5 is the future. The fourth page gets into how all of this history is leading Facebook to a precipice of change with HTML5 and the so-called Project Spartan.

Also note that Fetterman talks fast and occasionally swears. He is the classic Facebook engineer: kind of young, pretty brash and supremely confident. The transcript is as true to his actual words as possible.

Changing Mobile Standards Through The Past Five Years

We took an extreme HTML-based approach to this. So we will go into how we do this so you can learn how HTML5 is the way out of a lot of these problems.

Because, it wasn't really always this way for us. We have had the same mobile problems that you guys have. We are following the same mobile ecosystem that you guys are following to develop for your users.

So, we have the same problems of cross-platform development that you have and we are hoping that you can learn a little bit from us. So, we have been learning to deal with these issues with what we call 'FaceWeb' and learning a new opportunity to get out of this that is emerging as we speak called HTML5.

So, in 2006, building a mobile presence meant that you had a WAP deck that was based on an HTML application with SMS and all of that. But, as you all know, mobile changed fundamentally in 2007. What happened then?