9 of the Best Free Linux Debuggers Debugging is the process of finding and reducing the number of bugs in computer software and electronic hardware. When a program crashes, the debugger shows the position in the original code. A good debugger plays an essential role in software development. (Read more) Dia Dia is a gtk+ based diagram creation program released under the GPL license. Dia is designed to be much like the commercial Windows program 'Visio'. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship diagrams, UML diagrams, flowcharts, network diagrams, and simple circuits. It is also possible to add support for new shapes by writing simple XML files, using a subset of SVG to draw the shape. Read more