This contains three fonts: "Unifont" (unifont.pcf.gz), "Unifont CSUR" (unifont_csur.pcf.gz), and "Unifont Sample" (unifont_sample.pcf.gz).
This is a bitmap version of Unifont in a standard X11 format. The fonts provide a glyph for each visible code point (character) in the Unicode Basic Multilingual Plane (BMP, or Plane 0). The BMP contains most of the world's modern writing scripts. These fonts look best at 12pt.
unifont.pcf.gz contains Unicode Plane 0 glyphs. This is the main font.
unifont_sample.pcf.gz contains combining circles for combining characters. Thus it is suited for illustrating individual Unicode glyphs, whereas Unifont is intended for general-purpose writing.
unifont_csur.pcf.gz contains some scripts in the Plane 0 ConScript Unicode Registry (CSUR). These scripts are not part of the Unicode Standard, but are a popular use for the Private Use Area (PUA).
Complex fonts (such as Indic or Semitic scripts, where letters change shape depending on their position in a word, or such as Mongolian, which can be written vertically) will not render perfectly. The philosophy behind this font, though, is that anything meaningful is better than an empty box for an unknown glyph.
Consider using the TrueType version instead (fonts-unifont), because that version is scalable to any point size and has proper combining character support.