What mobile platform should I start learning? [closed]

Answer 1

Check Google for smartphones market share. Here is one from Gartner. In short, sales stats for 2008 are (sales is in thousands of units):

Operating                2008        Market          Growth
System                  Sales         Share       2007-2008
-----------------------------------------------------------
Symbian              72,933.5          52.4%           -6.1
Research In Motion   23,149.0          16.6%           96.7
MS Windows Mobile    16,498.1          11.8%           12.2
Mac OS X             11,417.5           8.2%          245.7
Linux                11,262.9           8.1%           -4.2
Palm OS               2,507.2           1.8%           42.2
Other OSs             1,519.7           1.1%           13.1
-----------------------------------------------------------
Total               139,287.9         100.0%           13.9

So, reading this, Symbian devices are biggest market. iPhone and BlackBerry are fast growing platforms. Android came on market late last year, so it's hard to say how popular would it be.
My pick would be:

1. iPhone - because it is most uniform platform - same display and keyboard, similar other features. Very popular web shop if you decide to go professional. Fast growing market share, possible number two in next year or two.
   Minus is that it requires Mac computer for development.
2. BlackBerry - relatively small number of different devices (different resolutions, different keyboards), but it complicates development because you need to take into account those factors. Second by sales number, keeps very high growth rate.
3. Symbian - by far largest number of phones, but from several different vendors (Nokia, Samsung, Sharp, Sony Erricson, ...) with number of different hardware configurations. Each vendor has its own developer program you need to join to get access to device specific SDKs.
4. Windows Mobile - still sells large number of units, very good development tools.
5. Android - ? On hold until it gains any significant market share.

Edit:
Re Mac comments:

• Cheapest Mac Mini (1 GB RAM, 120 GB HD) without mouse, keyboard and monitor cost as much as mid-range Dell or HP laptop ($599). So, minimal hardware needed for development cost at least two times more than a Windows based system. iPhone development requires more expensive equipment than any other smartphone platform. And that is a downside.

Re Symbian comments:

I know about symbian.org and the open source initiative. But:

1. The process is very slooow. It started more than 1 year ago (June 2008) and it's still beta. This is deal between very big companies and it will probably pass some time before they come to final agreement.
2. Now, if you want to develop for Symbian devices, you need to go to every vendors developer site to get access to documentation, examples, SDKs, tools ...
3. If you plan to go professional, every vendor has its own shop and set of rules that you'll need to comply.