This could be difficult, depending on the page.

There are two possible strategies that I can think of:

Use an IFrame to embed the pages is into drupal pages. You might consider using a module such as IFrame Filter to embed these pages directly.
Create custom modules to reap your PHP code, registering menu hooks for these. Basic strategy would be to replace javascript includes with drupal_add_js calls in the module, and use output buffering to scrape your data from the php application. If there’s a lot of attatched javascript that’s not in libraries this could be problematic.

From: support-bounces@drupal.org [mailto:support-bounces@drupal.org] On Behalf Of Scott Massey
Sent: Tuesday, June 21, 2011 10:29 AM
To: support@drupal.org
Subject: [support] Integrating completely unrelated pages into Drupal

Hi!

I am about 6 months into Drupal and enjoy it immensely. I am putting together a portfolio of some web development I have done and have several pages of data visualiztions using php and a javascript library called Protovis. If I want to bring that into drupal as a page, is there a way to do that? There are library calls, jquery, etc. I am having trouble wrapping my head around how to do it. I would like the pages to be a menu item that opens a page within the drupal site. Here is an example of a page:
http://modernamericanman.com/ids499/protovis7.php

Thanks!

Scott