Keystone architecture utilizes:
Keystone is a product information management (PIM) solution powered by Pimcore. Pimcore is arguably the best open source solution for product information management (PIM).
As Pimcore is open source and improves over time in the base system, Keystone upgrades with those changes as well.
Grey Wolf is integrating with your ERP system through Grey Wolf Web Services Lite (a prerequisite for Keystone).
Integration touch points include: