Install Autoconf, Automake and Libtool on Mac OS X

I am currently working on a speech recognition related project and want to install an open source library that does the backend computation on my laptop. 

To install the library, aclocal, autoconf, automake and libtool are required. 

However, according to some blog articles, Mac OS X stopped to support auto tools ever since Xcode 4.4.1. 

Below are scripts I learned from other bloggers to manually install auto tools:

export build=~/devtools # or wherever you'd like to build
mkdir -p $build

cd $build
curl -OL http://ftpmirror.gnu.org/autoconf/autoconf-2.68.tar.gz
tar xzf autoconf-2.68.tar.gz
cd autoconf-2.68
./configure --prefix=$build/autotools-bin
make
make install
export PATH=$PATH:$build/autotools-bin/bin

cd $build
curl -OL http://ftpmirror.gnu.org/automake/automake-1.11.tar.gz
tar xzf automake-1.11.tar.gz
cd automake-1.11
./configure --prefix=$build/autotools-bin
make
make install

cd $build
curl -OL http://ftpmirror.gnu.org/libtool/libtool-2.4.tar.gz
tar xzf libtool-2.4.tar.gz
cd libtool-2.4
./configure --prefix=$build/autotools-bin
make
make install