As Oracle and SAP consolidate their positions as the top two enterprise applications providers, more and more application development and delivery managers will have to account for these vendors' applications in their architectures and strategies. Both Oracle and SAP provide tools that middleware customers can use to extend and customize their enterprise applications as well as to build custom applications from scratch. The result: Application development and delivery managers can turn to both Oracle and SAP to: 1) buy; 2) build; or 3) buy and customize. The choices and the tradeoffs both vendors give application development and delivery pros are far from simple — and have grown more complex during the last two years.