Z00t

I needed to know how I can install truetype fonts on a Linux webserver and then use these fonts through PHP. I need to make dynamic PNG files through PHP and inserting comments in PNG's have been a task too hard to achieve for me. If truetype can be installed, does it come in a different file format for Linux/PHP than the one used in Windows (i.e the .TTF)? This might be too easy a question for most of you to answer and this may not be the relevant forum to ask but any help would be really appreciated.