In the first nine months of 2005, iRobot earned a profit of $2.6 million, compared with a $189,000 loss a year before. Revenue totaled $95.5 million, 66% higher than the year-ago period. And 87% of that came from sales of Roomba and PackBot, which iRobot sells only to the U.S. government, while the rest came from military contracts. In the third quarter alone, iRobot made $52.5 million, or more than half its entire revenue for the nine months. And that figure is likely to rise even more this quarter as Roomba sales pick up steam during the holiday season. Third-quarter profit came in at $9.7 million, or 19% of revenue. Although iRobot has only recently gained the attention of investors and consumers alike, it's been around since 1990, when it was invented by three of its current top executives: CEO Colin Angle, Chairman Helen Greiner and CTO Rodney Brooks (who still heads MIT's Computer Science and Artificial Intelligence Lab). A year later, the company produced its first robot, Ghengis, which was built to explore the surface of other planets. And it has since deployed robots to handle tasks from detecting and eliminating land mines to exploring the pyramids of Egypt. After a decade of government work, iRobot went after a holy grail of robotics -- a mobile robot as useful and sophisticated as an industrial robot but also as ubiquitous and affordable as a PC. Creating a handleless vacuum cleaner that wouldn't bump into walls or fall down stairs seemed like a good start. "They took a huge risk," says Neena Buck, a vice president at Strategy Analytics. But Roomba's success has become so big that other vacuum makers are looking into making their own copycat versions. iRobot's 21 patents and 25 pending patent applications, however, are likely to keep it ahead long enough to develop other robots for consumers.