मुक्तस्रोत(Open Source)

I am searching for some utility/library (free source) for pdf creation.
The requirement is to get the contents of current displayed page and convert it to pdf.
The language is PHP.
The user scenerio would be
1. User hits a link which does some computation and provides him/her results in the browser as a html page.
2. The HTML page has a button, which says "Download as PDF"
3. Once user clicks it, the contents of the page gets converted to PDF and user gets the dialog for saving it.

I am developing an application using Ruby on Rails.
Whenever I deploy my application at customer end using apache, I have to put all ruby files there.
My problem is I do not want to give these ruby scripts. My deployment is not on a web hosts where only I have an access. The deployment is in customer environment where he/she can access ruby scripts.
Customer/user can copy/modify the code. This way I have major problems
1. I can not have some activation/registration code logic for licensing. Customer can go and change the "if" logic.

फायरफॉक्स ३. ० खरोखरच भारतीय भाषांसाठी वरदान ठरणार आहे. आपण हा न्याहाळक (इंटरनेट एक्स्प्लोअर सारखा ब्राउझर) येथून मिळवू शकता...
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१) यात इंडीक इनपुट एक्स्टिंशन वापरून सहजगत्या मराठी लिपीत मजकूर टंकित करता येतो.