>The fragmentation issue in Mac OS X [1] is the hurdle that has been holding me off from writing apps for Macs.

Doesn't seem to be doing much damage to Mac software houses/indies...

>According to [1] (published about half a year ago), the Mac OS X market share breakdown: Mountain Lion 10.8 26.8% Lion 10.7 28% Snow Leopard 10.6 35.1% Leopard and lower 10%

So just target Lion and above, that's 54%, which might sound small, but it's tens of millions of users. Mac software houses thrived in 2005 with 1/4 the user base that what that 54% represents.

That said, I highly doubt SL is 35% still.