XSB is a Logic Programming and Deductive Database system for Unix and Windows. It has been developed at a number of institutions, including he Computer Science Department of Stony Brook University, Universidade Nova de Lisboa, XSB Inc., Coherent Knowledge Systems, Inc., and Johns Hopkins Applied Physics Lab.
XSB is kindly hosted by Sourceforge. You can directly access the following resources from here:
If you are new to XSB, please read the XSB Technical Summary for a (somewhat outdated) overview of its main features.
The latest stable version of XSB 5.1 has been fully tested and is available (October 13, 2026). See the release notes here.
While XSB is constantly updated we are lazy about putting out releases. Until we reform, you can also get the latest version of the code from the Sourceforge GIT repo.
The XSB download includes the manuals in pdf format, but they may also be downloaded separately: Volume 1 and Volume 2
These are a few of many projects that use XSB (contact us if you would like yours added).