title: How can we restore ppc/ppc64 as well as full 10.4/10.5 SDK support to Xcode 4?
body: <p>Since Apple only ships SDK 10.6 with Xcode4, developing PPC applications with Xcode4 became impossible. While it is possible to develop applications with Xcode4 that can also run on 10.5 and maybe even on 10.4 systems (by selecting SDK 10.6, but deployment target 10.5 or 10.4), they will only run on Intel Macs because you need at least SDK 10.5 for building PPC applications.</p>
  
  <p>Further there are some rare cases, where you really need to build against an SDK prior to 10.6 for full platform support, e.g. if certain deprecated functionality has vanished completely from the 10.6 SDK, but you'll have to use it and dynamic linking is not always the best option in those cases. Also linking against an earlier SDK sometimes will ease development as functionality you are not supposed to use, as it would cause incompatibility to earlier OS versions, won't be available and any attempt to use it anyhow immediately leads to compiler or linker errors.</p>
  
  <p>Last but not least Apple has also removed GCC 4.0 support from Xcode4, which may be necessary for certain software to build correctly and Apple has never allowed to compile software with GCC 4.2 when using SDK 10.4, even though I hardly believe that this would really cause any issues, after all software built with GCC 4.2 and SDK 10.6 can also run on Mac OS 10.4 without any issues as long as the deployment target has been set correctly and no functionality that is unavailable under MacOS 10.4 has been used.</p>
  
  <p>Of course you can always have a parallel installation of Xcode3 next to Xcode4, but that means you must forgo all the (great?) new features of Xcode4 and keep working with the outdated Xcode3 IDE. It would certainly be much better if you could also manage all your old projects within the same IDE as your new ones and benefit from any new features available. Not all projects can be made 10.6 or Intel only in the foreseeable future. Further I'm strictly against abolishing support for older platforms earlier than would be really necessary.</p>
  
  <p><strong>Can we restore this functionality to Xcode4?</strong></p>