Online stores and businesses have a hard time tracking what their customers are doing. This lack of knowledge about customer activity can result in thousands of dollars lost in the sales pipeline.

This second excerpt from Advanced PHP Programming: A practical guide to developing large-scale Web sites and applications with PHP 5 by George Schlossnagle is reprinted with permission of Sams ...

Joel Gratcyk's son Wesley spends a few hours a week learning to code in Python, PHP, and Swift. Wesley started taking free courses when he was 7 and uses both online and library resources. Gratcyk ...