While OS X El Capitan is not yet available to the public, Apple has gone ahead and seeded the first beta version of OS X 10.11.1 to developers. Interested developers can grab it now from the OS X Developer Resource Center.

Apple is not yet detailing the changes that will be found in OS X 10.11.1, or when we can expect it. However, with OS X El Capitan launching to consumers on September 30, we don't expect it to arrive until at least some time in October.