Update: 3.4.2017. this no longer works since homebrew/boneyard got obsoleted/deleted today.
If you try to install Cisco VPN concentrator client (vpnc) today, chances are you won't be able to since it was removed from regular homebrew formulae.
brew install vpnc Error: No available formula with the name "vpncc" ==> Searching for similarly named formulae... Error: No similarly named formulae found. ==> Searching taps... Error: No formulae found in taps.
However you can still install it from archive of homebrew formulae (boneyard):
brew cask install tuntap brew install homebrew/boneyard/vpnc
Be aware that this version of vpnc requires tuntap installed, also, it installs all this as dependencies:
brew deps vpnc gmp gnutls libffi libgcrypt libgpg-error libtasn1 libunistring nettle p11-kit
This will install last available, rather old vpnc version 0.5.3 dating back in 2006.
I found a new and modified version of vpnc on github modified for xnu (OS X 10.6+) and utun support so tuntap is not required. Unfortunately it is not yet in brew as formulae. However if you install all above dependencies, you will be able to build it easily your self:
git clone https://github.com/breiter/vpnc.git cd vpnc make sudo make install
This will install vpnc version 0.5.3-xnu-2015-07-03.
Both vpnc versions expect configuration to be present in