The IBM i development blog has heard from a user who has been told that Zend Core for System i is only free for the first year. Whether this is true for all customers or not is unclear, but here’s a snippet of what the end user has heard from Zend:

“We can install Zend Core for i5 and all nine developers can use Zend Studio for i5 and we can continue to utilize these products free of charge for one year and one year only. When the first, free year concludes, in order to continue using the Zend products, we will need to purchase…”

The IBM i development blog says that they’ve been using Zend on i for three years now with no demand for payments.

Update: It seems as though support for Zend Core is free only for the first year, but the software itself remains free past one year and beyond.