Debian/Ubuntu
The static side of TuxArena
Nano is a popular, user-friendly text editor for Linux which runs in console mode, without the need of an X server. By default, Nano comes with syntax highlighting for programming languages disabled, however it provides default rules for several languages like Perl, Python or C, among others. These highlighting definitions are kept inside the /usr/share/nano/ directory, and a file with rules corresponds to each language.

For example, ls /usr/share/nano/ will show the following output on my system, which has Nano 2.0.7 installed:
debian$ ls /usr/share/nano/
asm.nanorc    java.nanorc    patch.nanorc   ruby.nanorc
c.nanorc      man.nanorc     perl.nanorc    sh.nanorc
groff.nanorc  mutt.nanorc    pov.nanorc     tex.nanorc
html.nanorc   nanorc.nanorc  python.nanorc  nano-menu.xpm
In order to enable syntax highlighting in Nano based on one of these files, edit the ~/.nanorc file (or create it if it doesn't exist), where ~ is your home directory, and add lines like this:
include "/usr/share/nano/c.nanorc"
include "/usr/share/nano/perl.nanorc"
include "/usr/share/nano/sh.nanorc"
These three lines will include the files c.nanorc, perl.nanorc and sh.nanorc, which will define highlighting rules for C, Perl and Bash respectively. This can also be accomplished by copying the contents of one file directory into ~/.nanorc. For example:
cat /usr/share/nano/c.nanorc >> ~/.nanorc
This will append the contents of /usr/share/nano/c.nanorc at the end of ~/.nanorc. You can also search on Google for other rules, which fit better with your taste (e.g. provide different colors or are more precise).