Adobe Acrobat is a program for creating PDF files and converting other file formats to PDF. It also allows you to change text and stuff in the PDF without having to re-export it.
It is a MicrosoftWindows and Macintosh only program.
There is however a free AcrobatReader that allows you to view PDF files - this has a Linux version. Or you could use xpdf(1) or gv(1).
See CreatingPDFs for other programs that can generate PDF files.