PHPTAL is released as a PEAR package (see pear.php.net). You can download the PHPTAL library on the PHPTAL website: phptal.org.
You can install it using the PEAR utility:
pear install http://phptal.org/latest.tar.gz
Once installed, you can upgrade PHPTAL easily on each PHPTAL update using PEAR:
pear upgrade http://phptal.org/latest.tar.gz
If you do not use PEAR or do not have it installed on your system, you can still install PHPTAL by unzipping the downloaded archive.
tar zxvf PHPTAL-X.X.X.tar.gz
cp -r PHPTAL-X.X.X/PHPTAL* /path/to/your/lib/folder
This will install the PHPTAL.php file and the associated PHPTAL folder in /path/to/your/lib/folder.