I have only seen it in conjunction with Ninja.
By the way, I learned something new about zen-fire. Apparently zen-fire Eurex feed has a major flow. Every single trade that comes through has a volume of 99 contracts. So if you use volume or Times@ Sales, it becomes pretty useless. If you do not need them, then zen-fire is fine for Eurex.
I had zen-fire and tt side by side displaying DAX futures DOM, and the refresh rate was identical.