LISFS: a logical information system as a file system

We present Logical Information Systems (LIS). A LIS can be viewed as a schema-less database whose objects are described by logical formulas. Objects are automatically organized according to their logical description, and logical formulas can be used for representing both queries and navigation links. The key feature of a LIS is that it answers a query with a set of navigation links expressed in the same logic as the query. As navigation links are dynamically computed from any query, and can be used as query increments, it follows that querying and navigation steps can be combined in any order.We then present LISFS, a file-system implementation of a LIS, where objects are files or parts of files. This has the benefit to make LIS features available right now to existing applications. This implementation can easily be extended and specialized through a plug-in mechanism.Finally, we present some applications in the field of personal databases (e.g., music, images, emails) and in the field of software engineering.