Gtk2::sourceview2 is the perl binding for the c library gtksourceview-2.0. this is the same widget that's used by gedit, monodevelop, anjuta and several other projects.

this widget extends the standard gtk+ framework for multiline text editing with support for configurable syntax highlighting, unlimited undo/redo, utf-8 compliant caseless searching, printing and other features typical of a source code editor.

for more information about gtksourceview-2.0 see: http://projects.gnome.org/gtksourceview/.