For interest’s sake, here’s my graph of Mac OS X build numbers v release date for Tiger and Leopard. This assumes a Leopard release date of 15th October.
I guess things to note are that the gradients of the graphs seem roughly the same, so the rate of development seems unchanged (no dramatic improvements in software development methodology or tools in the 2 years (I guess that includes XCode 3 :)).
Also, it seems that Leopard will have had about an extra 150 builds by the time it’s released compared to the Tiger release build. At the time Apple announced the delay of Leopard due to the iPhone (2007-04-12) it was 186 days before October 15th. At the time of that announcement the Leopard build number was about the same as at which Apple shipped Tiger.
When a bug is submitted to Apple via http://bugreporter.apple.com/ it’s allocated a RADAR number. By poking around for some dates and RADAR numbers it’s possible to get a rough idea of how many RADAR issues are being added per day. Of course this assumes that they’re allocated in contiguous numerical order. But we can see that even if they’re getting a conservative 1600/day that’s a lot to sort through, allocate as duplicates, request more information, and assign to the appropriate engineering effort. I’m not sure if this includes crash reports that are filed automatically from Mac OS X either.
Apple engineers repeatedly say that the company is bug driven, so it’s good to see they’re getting so many reports logged 🙂