Perl is a high-level, general-purpose programming language that makes easy things easy and hard things possible. It is optimized for scanning arbitrary text files and system administration. It has built-in extended regular expression matching and replacement, a dataflow mechanism to improve security with setuid scripts and is extensible via modules that can interface to C libraries.
The Jikes Debugger is a multi-paneled graphical debugger that allows you to inspect the current state of a remotely executing Java program. The debugger allows you to view program threads, call stacks, local variables, classes, and source files during execution. It is written in Java and uses the java.awt package to generate the graphics and the sun.tools.debug package to run the remote virtual machine. The Jikes Debugger is written in pure java and should work on Linux (the source code is available).
perldbgui is a GUI for the standard Perl debugger. The GUI consists of two windows: one is a console window that's just like the regular perl debugger, the other is a source window that displays the executing source code. From the source window you can load other files, execute commonly used commands with buttons at the bottom, and execute almost any debugger command with keyboard shortcuts.
g2 is an easy to use, portable and powerful 2D graphics library. It provides a comprehensive set of functions for simultaneous generation of graphical output on different types of devices. The following devices are currently supported: Postscript, X11, FIG (xfig), PNG, and JPEG using the gd library, and Win32. g2 is written in C (ANSI) and additionally has Fortran, Perl, and Python interfaces.