Microsoft has opened up testing of a web-based service that allows parents to control what their children do on the internet.

The service, called Windows Live OneCare Family Safety, is now available for trial in the US, according to Microsoft. It can be downloaded on the Windows Live Ideas website.

"While we are still in the testing and development phase, OneCare Safety will offer some great features to help families create a safer and enjoyable online experience," Microsoft said in a blog posting on the software's release.

The Family Safety service has been available to a limited set of beta testers since earlier this year, but this is the first time that Microsoft has opened up to the general public. The company is not saying when users outside of the US will be able to try out this product, but more information about that will be released "very soon", Microsoft said.

Family Safety lets parents block their kids from viewing sites relating to inappropriate subjects such as pornography or alcohol. They can also get activity reports on what sites their children have been visiting. Because Family Safety is a web-based service, parents can adjust settings or check in on their kids from any internet-enabled PC.

Microsoft is also offering guidelines on how children can use the internet safely and tips on how parents can talk to kids about their online activity.

Future versions of the service will let parents create 'allow' lists to help them control their children's use of other Windows Live services such as instant messaging.

The Windows Live services are part of Microsoft's broader effort to take on competitors such as Google, which has focused on creating software that is hosted on the internet, rather than written for Microsoft's Windows OS (operating system).