Apple has closed down its KidSafe iTools service, citing low customer usage.

The company released an email to iTools customers late Friday announcing its decision. It said: "Apple encourages you to continue monitoring your children's use of the Internet and be active in preventing them from accessing inappropriate content."

Apple CEO Steve Jobs introduced KidSafe during his keynote speech on January 5, 2000. It's the second iTools service to be discontinued - the company closed down its iReview service this year.