Yesterday Apple released the first previews of both iOS 9 and OS X El Capitan. We are working full-speed to add support for both iOS 9 and El Capitan right now, and we’ll keep you posted as things progress.
For iOS 9, we are investigating an issue that is causing a number of Xamarin apps to crash on startup. As we’re digging into this, the issue seems to be specific to apps that include 32-bit support.
Apple made some dramatic changes to OS X by making /usr/bin read-only, even with root access, so we’re working on making support for Xamarin Studio and the Xamarin Installer available as soon as possible to get up and running on OS X El Capitan.
As always, these are preview builds and we recommend staying with the stable releases of Xamarin and OS X and iOS until we make full support available for these previews available via this release blog and their preview sites.
Update: We have identified two issues that will affect both 32-bit and 64-bit apps on iOS 9. This has been released as a hotfix which you can find more detail on our hotfix blog post.