Dia is a free program that can be an alternative to Microsoft Visio and other such tools. Allows you to create a variety of presentation graphics - block diagrams, diagrams and diagrams. A symbol library is available that includes universal UML symbols (used in object analysis and object programming) as well as symbols from a wide range of disciplines such as electrical engineering, computers, civil engineering, etc.

The library is also available in the form of a library of symbols. The program uses its own DIA format based on XML language, it also enables reading and writing in DXF and SVG formats. Unfortunately, Visio VDX and VSX files are not supported.

The interface of the program resembles the popular GIMP, which is the result of using the same GTK+ libraries. In order to obtain the Polish interface, after installation, you need to start, shut down and restart the program.