Write one name per line on the left. A line indented with a tab becomes a child of the line above it, and two names joined with "+" become a couple. A couple can have any number of children, and each child can marry and have children of their own.
Generations and siblings are arranged automatically, with marriage lines between partners and descent lines down to the children. The whole chart is always fitted into the view.
Vertical text stacks the characters top to bottom; horizontal text sets them on one line. You can adjust font size, generation spacing, sibling spacing, and borders, and save the finished chart as a PNG.