I'm going to prepare a prototype for a software. It will written with PHP. Which software can I use to do that. I need to design all pages before they are developed.
Thanks for your guide.
What is the purpose of the prototype? If it's just to show the client how it will work you're almost certainly better off just doing some visuals, either in HTML or just some mock ups in photoshop of the different aspects of the site.
For creating a rapid prototype or wireframes I've used Axure in the past. It's not free, but it's quite powerful.
I once used it to create such a nice wireframe that the client thought we'd finished the project way ahead of time and were delivering the final version
If you're simply interested in showing the customer what the pages will look like once they are finished and what they can do, I'd suggest you take a look at Balsamiq Mockups. I use that application to write each functional specification and the clarity it provides in communication with the client has saved me a ton of hassles.
Perhaps you can use an integrated wysiwyg editor/IDE. Popular choices are Dreamweaver, Zend Studio, Komodo (And many more).