DEPS (formerly known as graph-includes) is a set of tools and libraries which allows users to extract dependency information from arbitrary material (e.g. program source files), apply various transformations to this graph, and draw it. It is typically used as helper tool for a refactoring effort, to create a graph of dependencies between groups of source files. Readability and usability of the dependency graphs are currently improved by customizable grouping of several source files into a single node, coloring of nodes belonging to given groups, and transitive reduction of the graph.
Autodia is a command line Perl application that generates UML class diagrams from source code, SQL, and database connections. It supports multiple programming languages including SQL, and can output images (using GraphViz/VCG/SpringGraph), Dia XML and Umbrello XML, or custom formats using templates.
Perl::Critic is an extensible framework for creating and applying coding standards to Perl source code. Essentially, it is a static source code analysis engine. It is distributed with a number of Perl::Critic::Policy modules that attempt to enforce various coding guidelines. Most Policy modules are based on Damian Conway's book Perl Best Practices. However, Perl::Critic is not limited to PBP, and will even support Policies that contradict Conway. You can enable, disable, and customize those Polices through the Perl::Critic interface. You can also create new Policy modules that suit your own tastes.