It’s a mobile world, but we have not fully abandoned the desktop. The real work (and a lot of the play) of computing requires a full personal computing system, and to get the most out of that, you need software.
Software can be expensive, but free programs have been a mainstay of the desktop experience for decades, and today’s offerings are pretty powerful. Software developers can adopt an ad-based model, donation-ware to keep things afloat, or a shareware/freemium model that charges for extra features.
Something to always watch for: crapware installers. To make ends meet, many creators of otherwise great free software, or the services that offer the programs for download, bundle in things you don’t want. Worse, the installation routine obfuscates the steps, so you provide the unwanted program tacit permission to be installed. For more about how to spot and avoid this problem, see How to Rid a New PC of Crapware, and check out the Uninstaller section below.
A pro tip: only download desktop software from the maker of the software directly. It’s not foolproof—after all, developers want to eat, too—but it helps. That’s why one of the criteria for inclusion here is that the program is available directly from its maker.