Microsoft has taken an unusual step. It has relaxed a strict rule and will let employees moonlight in their spare time and keep the resulting intellectual property and most of the revenue, as long as that second job is writing apps for Windows Phone 7-based devices.

Free Windows 7-based phones were given to all employees in the 19 countries where the phones are available.

Mr. Watson of Microsoft said the policy change emerged in part because of a push from his group. “We tend to have strict moonlighting rules,” he said of the company. “But we’ve changed those rules so developers can do this in their spare time, and have the financial benefit and outcome of the work.”

The company is offering what Mr. Watson said was a standard split on app sales: 70 percent to the developers, 30 percent to Microsoft.

The incentive seems to be helping. More than 3,000 employees have registered to submit apps, he said, and about 840 have been published so far.