You have a moral obligation to use free software. At least, that's the message that Patrick Ball is trying to get out.

Ball is deputy director of the Science and Human Rights Program of the American Association for the Advancement of Science. He's best known for his analysis of the Kosovo refugee movements during NATO's bombing campaign in 1999. Now Ball is on another kind of mission: he's telling the world's 10,000 human-rights groups to stop using pirated copies of Microsoft Windows and Microsoft Office and trying to persuade them to use free software instead.

The best-known examples of free software are the GNU/Linux-based operating system and OpenOffice-an application suite that includes a decent word processor, spreadsheet, and presentation package. You can legally make as many copies of these programs as you want. Moreover, because this software is distributed with its source code, any programmer can examine the code, fix bugs, and tinker with the software's features.

Unlike some other advocates of free software, Ball is not fundamentally opposed to Microsoft or other commercial-software makers. But he worries that too many people put themselves in jeopardy by illegally copying programs from these companies. Ball is especially concerned about overseas human-rights organizations, but his argument is universal.