A interesting n-tier full Visual Foxpro is the Workframe ActiveVFP, this operate at Rules bussiness tier(the second tier typical n-tier enviroment)

The three tipical tiers in a n-tier enviroment:
1-User interface(fat client, think client)
2-Rules bussiness.(COM. object)
3-Data(VFP data source, SQL, ORACLE etc)

Att.