I'm going to help my friend in a improve of his phpBB board, but I want to make somethings there in Python or Perl. But it's possible to integrate these languages with PHP?
You can always call the python or perl interpreter from within PHP! Minimalistic interchange is possible by means of passing command line arguments and capturing stdout (exec or passthru are related php functions).
However, I don't think its's a good idea - using two interpreters instead of one doubles the overall runtime overhead and startup time.
Integrating Python or Perl with PHP