NEdit is a popular text editor for X, which features syntax hilighting for the following: plain text, Ada, Awk, C++, C, CSS, Csh, FORTRAN, Java, JavaScript, LaTeX, Lex, Makefile, Matlab, NEdit Macro, Pascal, Perl, PostScript, Python, Regex, SGML HTML, SQL, Sh Ksh Bash, Tcl, VHDL, Verilog, XML, X Resources, and Yacc. It also has such other features as auto-indent, parenthases matching, and a C-like macro language thingy.