Dia

Anyone who wants something lighter and more easily operable software that does much the same stuff as Visio, could certainly give Dia a try. This flexible software is very user friendly and has many features that could help you make casual flowcharts, diagrams etc. for representing process flows. The special objects available help you with entity relationships, UML diagrams, network connections and flowcharts. You can expand it further through easily modifiable xml files too. This software is also useful for loading the diagrams in an xml file and then by default save it in a zip format. This helps in easy transfer of data as well.