Windows/Linux only: Open-source application Dia is a robust flowchart and diagram tool. Like a free version of Microsoft Visio, Dia provides you with all the tools you need to create anything from a simple flowchart to a powerful and complex diagram, and files can be saved in many formats, including a Visio Drawing-compatible VDX filetype. Dia is free, Windows and Linux only. If you'd prefer build
![Dia Does Powerful Diagrams and Flowcharts](https://cdn-ak-scissors.b.st-hatena.com/image/square/d7e6a6f5469cad912e746d908411e51ca810f9c1/height=288;version=1;width=512/https%3A%2F%2Fx.kinja-static.com%2Fassets%2Fimages%2Flogos%2Fplaceholders%2Flifehacker.png)