The Walton Family Foundation is announcing its plans today to donate $25.5 million to the Knowledge is Power Program, or KIPP, charter network.

The Bentonville, Arkansas-based foundation, created by Wal-Mart founders Sam and Helen Walton, has been a longtime supporter of KIPP schools. But this award is the foundation's largest gift to KIPP so far. It's intended to provide support to help double the number of students attending KIPP schools by 2015, raising the number of children enrol...