There are several font packages for Linux. Many of them are obsolete, or you really will never have to use them.
chkfontpath is a utility for manipulating the xfs configuration file.
fontinst is a LaTeX package designed to simplify the installation of Type 1 fonts into LaTeX.
Freetype is a TrueType library that comes with most Linux distributions
Ghostscript is the software that is used for printing on Linux. The version of ghostscript that ships with Linux is GNU ghostscript. This is one version behind the latest release of Aladdin ghostscript ( who release their old versions under the GPL)
pfm2afm is a utility for converting windows pfm font metric files into afm metrics that can be used for Linux. This is based on the original version available at CTAN, and includes modifications from Rod Smith to make it compile under Linux.
mminstance and t1utils are two packages for handling Type 1 fonts. mminstance is for handling Adobe's multiple master Type 1 fonts. t1utils is a suite of utilities for converting between the different Type 1 formats.
ttf2pt1 is a TrueType to Type 1 font converter. It is useful if you have applications that require Type 1 fonts.
ttfps converts .ttf TrueType font files into Type42 files.
ttfutils A package of utilities for handling TrueType fonts. This package requires ttf2pt1. Useful if not essential.
type1inst is an essential package for installing Type 1 fonts. It greatly simplifies the installation.
xfstt is a TrueType font server for Linux. It's useful, but xfs is probably a better choice.
xfsft The xfsft font server. Note that this is included in xfs.
x-tt is a font server designed to handle Korean and Japanese fonts.