For Ubuntu Linux

Install PHP-Pear and libYAML

sudo apt-get install php-pear libyaml-dev
pecl install yaml

Now edit your php.ini file located at

/etc/php5/apache2/php.ini

and add

extension=yaml.so

Restart Apache2

sudo service apache2 restart

For Windows

Download this Pre-Compiled libYAML file.

http://search.4shared.com/postDownload/ComqwjFvce/php_yaml-102-dev-54-vc9-x86.html

and extract it in its respective places:

For XAMPP Users

Place this file:

yaml.dll

alone at the XAMPP Directory examle Directory:

C:\xampp\

and then, place this file:

php_yaml.dll

at XAMPP PHP Extention Directory.

Default Directory:

C:\xampp\php\ext

Now edit your php.ini file located at:

C:\xampp\php\php.ini

and add

extension=php_yaml.dll

Restart Apache via XAMPP Control Panel

For NON-XAMPP Users

• Copy yaml.dll to PHP root directory
• Copy php_yaml.dll to PHP/ext directory
• Add extension=php_yaml.dll to php.ini
• Restart Apache