GtkSourceView is a text widget that extends the standard GTK+ 3.x text widget
 GtkTextView. It improves GtkTextView by implementing syntax highlighting and
 other features typical of a source editor.
 .
 This package contains the language specifications files for Ada, C, C++, C#,
 CSS, ".desktop", ".diff" (patch), Fortran 95, GtkRC, Haskell, HTML, IDL,
 ".ini", Java, JavaScript, LaTeX, Lua, MSIL, Nemerle, Pascal, Perl, PHP, ".po"
 (gettext), Python, R, Ruby, sh, SQL, Tcl, Texinfo, VB.NET, Verilog, VHDL and
 XML.