Graphviz is open source software for graph visualization, representing structural information as diagrams of abstract graphs and networks. The package includes web and interactive graphical interfaces, and auxiliary tools, libraries, and language bindings.
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Originally developed for text manipulation, it is now used for a wide range of tasks including graphics programming, system administration, network programming, applications that require database access and CGI programming on the Web.
PostgreSQL is a powerful, open source object-relational database system running on all major platforms. Support for native programming interfaces for C/C++, Java, .Net, Perl, Python, Ruby, Tcl and ODBC among others.
A general-purpose high-level programming language that places an emphasis upon code readability. Python supports a number of development models, including object oriented, imperative, and functional design. It provides automatic memory management and a fully dynamic type system.