As of December 31, 2018, FreeSWITCH is no longer tested on OS X El Capitan. Apple dropped support and no longer issues security patches. Homebrew also no longer officially supports El Capitan.
FreeSWITCH installed and worked fine on El Capitan as of the dates below. If desired, follow the Xcode instructions below, then follow the manual installation instructions.
Xcode takes a while to download and is placed into the Applications folder (/Applications directory) with the Command Line Tools in /Applications/Xcode.app/Contents/Developer.
The Xcode Downloads require you to sign in with your Apple ID and agree to the Software Agreement:
El Capitan 10.11: download and install Xcode 7.3.1 from Xcode 7.3.1 Download then start Xcode. NOTE: Xcode 8 CANNOT be used. See FS-9521.
For OS X 10.11 and 10.12: NEVER delete the /usr/local directory! It's very difficult to recreate, it must be restored from a backup. This is due to System Integrity Protection (aka rootless) security.
As of July 17, 2016, the page below is no longer maintained by the original author and is marked as archived. It is replaced by these instructions: macOS Developer Tools.
This is part of the macOS Installation guide for installing and running FreeSWITCH™. This page describes the installation of components that may be unique to OS X 10.11.
The OS X Developer Tools are composed of two parts, the Xcode 7 OS X Software Developer Kit used to develop and test OS X GUI applications, and the Command Line Tools that provide LLVM, Clang, Git and other tools required to generate non-GUI applications such as FreeSWITCH™ and its prerequisites. The Command Line Tools are included and automatically installed with Xcode. The Apple Developer site offers the standalone CLT but it cannot be used because Homebrew will not install without the Xcode/CLT version.
Install Xcode using the OS X App Store application or download it from the OS X Developer site which requires a minimum of a free membership. Xcode takes a while to download and is placed into the Applications folder (/Applications directory) with the CLT in /Applications/Xcode.app/Contents/Developer. Once installed start Xcode to accept the license agreement.
Continue at Installation and Testing on OS X - Installation is Complete.