The GNU Unifont by Roman Czyborra is a free bitmap font that covers the Unicode Basic Multilingual Plane (BMP), using an intermediate bitmapped font format. It is present in most free operating systems and windowing systems such as Linux, XFree86 or the X.Org Server and some minor embedded devices like cell phones or microcontrollers. The font is released under the GNU General Public License.
Despite the prefix GNU in its name, GNU Unifont is not part of the GNU Project.
Read more about GNU Unifont: Status, The .hex Font Format, Vectorization