Well, we have. It's called DynamoRIO. It is the first software system that can manipulate, at runtime, every instruction an arbitrary application executes, with close to native performance and full transparency. DynamoRIO is comprehensive: it handles dynamic behavior, including dynamically-loaded, generated, and even modified code, and it allows fine-grained code manipulation on any part of the instruction stream. It requires no modification to the hardware, operating system, or application, nor access to application source code. Finally, our system is customizable, supporting the creation of custom tools.