The Kleisli Query System is a system designed for the broad-scale integration problems that have the following characteristics:

There are several key ideas that makes Kleisli a successful system:

The system is currently deployed mainly in the bioinformatics area. It is the first system that cracked many of the so-called ``impossible queries'' in the Human Genome Project in 1993.

In spite of Kleisli's sophistication, the source codes size of its core is remarkably small at 28k lines. I attribute this mainly to the fact that Kleisli is implemented on top of a functional programming system---Standard ML of New Jersey.

--- Limsoon Wong