To get the Linux edition of Praat, you either do sudo apt-get install praat, or you get it from Debian, or you compile it yourself from the source code, or you download a 64- or 32-bit binary executable on this page. These binaries will only work on Intel and compatible computers.
The binary executable requires the GTK and asound libraries on your computer, and at least version 2.11 of the C library.
To download Praat from this page, click on the appropriate compressed archive:
Unpack with gunzip and tar xvf. This will create the executable file praat. You can remove the tar file.
That depends on your operating system: if you have a 64-bit Linux, use the 64-bit edition, and if you have a 32-bit Linux, use the 32-bit edition. However, Praat's 64-bit edition can work with much larger sound files than the 32-bit edition and is not restricted to having 2 GB in its memory, so if you are still using a 32-bit operating system, consider upgrading to a 64-bit operating system if your computer supports it.
Praat will work fine wherever it is on your disk; just type praat or click the icon. If you use Praat for the first time, choose Intro from the Help menu.
If you want to see good phonetic characters, you have to install the Charis SIL and the Doulos SIL font, for instance from the packages ttf-sil-charis and ttt-sil-doulos on Debian or Ubuntu. If you cannot install those packages, you can download the two fonts from Summer Institute of Linguistics and follow the installation instructions there.
1. Sound not working?
Audio on Linux is notoriously fragile. Praat uses the Alsa sound system (or PulseAudio through Alsa), so that if audio does not work in Praat, it may still work in some other applications, like those that come with Ubuntu and use PulseAudio instead of Alsa (or Alsa through PulseAudio). The Ubuntu website suggests 16 steps that you may try to get audio to work.