if you don't want to install homebrew (or any other package manager) just for installing maven, you can grab the binary from their site:
http://maven.apache.org/download.cgi
extract the content to a folder (e.g. /Applications/apache-maven-3.1.1
) with
$ tar -xvf apache-maven-3.1.1-bin.tar.gz
and finally adjust your ~/.bash_profile
with any texteditor you like to include
export M2_HOME=/Applications/apache-maven-3.1.1
export PATH=$PATH:$M2_HOME/bin
restart the terminal and test it with
$ mvn -version
Apache Maven 3.1.1 (0728685237757ffbf44136acec0402957f723d9a; 2013-09-17 17:22:22+0200)
Maven home: /Applications/apache-maven-3.1.1
Java version: 1.6.0_65, vendor: Apple Inc.
Java home: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
Default locale: de_DE, platform encoding: MacRoman
OS name: "mac os x", version: "10.9", arch: "x86_64", family: "mac"