Knoppix is a 32-bit Debian Linux based distro, but recent releases (including the latest version 7.6) have also been equipped with a 64-bit kernel on the DVD edition, where it will automatically boot up for 64-bit computers, or by using the boot option codice_3 manually in the command-line prompt, while codice_4 will boot up the 32-bit kernel. Neither PAE nor 64-bit applications are supported by Knoppix, and system memory with more than 4 GB can only be used with a 64-bit kernel.