Best free software for students
yEd (Windows, Mac, Linux)
The paid (and briliant) OmniGraffle Pro is the king of diagramming apps, but yEd is its freebie nemesis. It’s not quite as clean as OmniGraffle, but it doesn’t want for power and it’s easy to use. It’ll import data from spreadsheets, intelligently neaten your messy diagramatical dog dinners and export in your favourite flavour of file. Essential.