Yellow Dog Linux (YDL) was a free and open-source operating system for high-performance computing on multi-core processor computer architectures. It focuses on GPU systems and computers using the POWER7. YDL was developed by Fixstars (which acquired Terra Soft Solutions, the original developer, from CEO Kai Staats in October 2008). Yellow Dog Linux was first released in the spring of 1999 for the Apple Macintosh PowerPC-based computers. The most recent version, Yellow Dog Linux 7, was released on August 6, 2012. Yellow Dog Linux lent its name to the popular YUM Linux software updater, derived from YDL's YUP (Yellowdog UPdater) and thus called Yellowdog Updater, Modified

Yellow Dog Linux was based on Red Hat Enterprise Linux/CentOS and relied on the RPM Package Manager. Its software included applications such as Ekiga (a voice-over-IP and videoconferencing application), GIMP (a raster graphics editor), Gnash (a free Adobe Flash player), gThumb (an image viewer), the Mozilla Firefox Web browser, the Mozilla Thunderbird e-mail and news client, the OpenOffice.org productivity suite, Pidgin (an instant messaging and IRC client), the Rhythmbox music player, and the Noatun and Totem media players.

Starting with YDL version 5.0 'Phoenix,' Enlightenment was the default desktop environment in Yellow Dog Linux, although GNOME and KDE were also included.

Like other Linux distributions, Yellow Dog Linux supported software development with GCC (compiled with support for C, C++, Java, and Fortran), the GNU C Library, GDB, GLib, the GTK+ toolkit, Python, the Qt toolkit, Ruby and Tcl. Standard text editors such as Vim and Emacs were complemented with IDEs such as Eclipse and KDevelop, as well as by graphical debuggers such as KDbg. Standard document preparation tools such as TeX and LaTeX were also included.

Yellow Dog Linux included software for running a Web server (such as Apache/httpd, Perl, and PHP), database server (such as MySQL and PostgreSQL), and network server (NFS and Webmin). Additional software was also included for running an enterprise server or a compute server or cluster, although two separate products from Terra Soft Solutions, called Yellow Dog Enterprise Linux (for enterprise servers) and Y-HPC (for compute servers/clusters), were specifically targeted toward those applications.

Although several other Linux distributions support the Power ISA, Yellow Dog Linux was distinguished for its focus on supporting the Apple Macintosh platform before the Mac transition to Intel processors. Before this transition, Terra Soft Solutions held the unique distinction of being the only company licensed by Apple to resell Apple computers with Linux pre-installed (or for that matter, with any operating system other than Mac OS X). Full support for AirPort (Apple's implementation of the IEEE 802.11b-1999 wireless networking standard), and partial support for AirPort Extreme, are also built into Yellow Dog Linux, as are support for Bluetooth and support for accessing the Internet over cellular phones.

Following the Mac transition to Intel processors, Yellow Dog Linux retargeted version 5 and later to support the Sony PlayStation 3 and IBM pSeries platforms extensively, while retaining its longstanding support for PowerPC-based Apple hardware.