All the engineering students and professionals need to draw diagrams of some kind. Dia is just a tool for it. You can draw verious kind of diagrams like entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and many other diagrams.

    It is available for linux as well as windows. As it is open source, source code is also available for download.

Dia is roughly inspired by the Microsoft Visio software, but its free! :)

    It can load and save diagrams to a custom XML format (gzipped by default, to save space), can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages). (paragraph copied from official dia website )

    You can get Dia from here ( http://live.gnome.org/Dia ).