A central duty of the laboratory is to inform clinicians about the availability and usefulness of laboratory testing. In this report, we describe a new class of laboratory middleware that connects the traditional clinical laboratory information system with the rest of the enterprise, facilitating information flow about testing services. We demonstrate the value of this approach in efficiently supporting an inpatient order entry application. We also show that order entry monitoring and iterative middleware updates can enhance ordering efficiency and promote improved ordering practices. Furthermore, we demonstrate the value of algorithmic approaches to improve the accuracy and completeness of laboratory test searches. We conclude with a discussion of design recommendations for middleware applications and discuss the potential role of middleware as a sharable, centralized repository of laboratory test information.