Xero is accounting software for people who never wanted to learn accounting. Rod Drury and Hamish Edwards started it in Wellington in 2006, and the whole interface follows from one bet: a café owner should be able to reconcile a bank feed without knowing what a general ledger is.

The result is a white ledger. White cards and invoice rows sit on a barely-blue canvas, a sky-blue circle marks the top-left corner, and deep navy appears only as ink. Numbers are tabular, right-aligned and easy to read at a glance.