could it be referring to a Zack system?

Ihave found references to various types of Zack system on the web, and Zack would appear to be the name of the company...

Product Overview
Zack's edge application servers allow network service providers and enterprises to harness the power of their network edge. Each of Zack's servers operates as a proxy, sitting between users and the Web to deliver a broad range of applications to end users without client-side downloads. The servers work in conjunction with existing network architecture and do not interfere with existing caching systems or other server networks.