This is an old revision of the document!
PHPTAL is licensed under LGPL (v2.1 or later).
The licence does not "infect" other software you use with PHPTAL, so it's safe for commercial use.
You only have obligations if you modify PHPTAL files and redistribute them (and sending HTML from the server doesn't count as redistribution).
IANAL. This page is only non-legally-binding summary.