Libdvdcss

libdvdcss (or libdvdcss2 in some repositories) is a free and open source software library for accessing and unscrambling DVDs encrypted with the Content Scramble System (CSS). libdvdcss is part of the VideoLAN project and is used by VLC media player and other DVD player software packages, such as Ogle, xine-based players, and MPlayer.

libdvdcss is not to be confused with DeCSS. Whereas DeCSS uses a cracked DVD player key to perform authentication, libdvdcss uses a generated list of possible player keys. If none of them works (for instance, when the DVD drive enforces region coding), libdvdcss then performs a brute-force attack, ignoring the DVD's region code (if any). Unlike DeCSS, libdvdcss has never been legally challenged.

Many GNU/Linux distributions do not contain libdvdcss (for example, Debian, Fedora, SUSE Linux, and Ubuntu) due to fears of running afoul of DMCA-style laws, but they often provide the tools to let the user install it themselves. For example, it used to be available in Ubuntu through Medibuntu, which is no longer available.

Distributions which come pre-installed with libdvdcss include BackTrack, CrunchBang Linux, LinuxMCE, Linux Mint, PCLinuxOS, Puppy Linux 4.2.1, Slax, Super OS, Pardus, and XBMC Live.