The Isabelle System Distribution

Version information

This is the internal repository version of Isabelle. See the NEWS file in the distribution for details on user-relevant changes.

System requirements

Isabelle requires a real Unix box with sufficient resources, say 64 MB of free main memory and a decent CPU. Speaking by today's hardware standards, any moderate Linux box should give a very nice platform for Isabelle.

Furthermore, Isabelle needs the following software, which is not part of the distribution:

The following ML system and platform combinations are known to work very well:

Poly/ML, previously a commercial product, is back in the free world. It is by far the best compiler for running Isabelle, requiring the least memory and offering the highest performance.

SML/NJ needs more store and disk space, but on the other hand supports more platforms. The current official release is 110.


Binary packages are available for Isabelle/HOL and ZF for several platforms from the Isabelle web page. The system may be easily built from scratch as well, taking the traditional tar.gz source distribution. See file INSTALL as distributed with Isabelle for more information. Further background information may be found in the Isabelle System Manual, distributed with the sources (directory doc).

User interface

The canonical Isabelle user interface is Proof General by David Aspinall and others. It is a generic (X)Emacs interface for proof assistants, including Isabelle (both for the classic and Isar version). Proof General is suitable for use by pacifists and Emacs militants alike. Its most prominent feature is script management, providing a metaphor of live proof script editing. Proof General has recently gained a rather large following of both beginning and expert users of Isabelle.

Proof General is distributed together with the XEmacs X-Symbol package, which provides a nice way to get proper mathematical symbols displayed on screen.

Other sources of information

The Isabelle Page

The Isabelle home page may be accessed both from Cambridge and Munich:

Mailing list

The electronic mailing list provides a forum for Isabelle users to discuss problems and exchange information. To join, send a message to

Personal mail

Lawrence C Paulson
Computer Laboratory
University of Cambridge
JJ Thomson Avenue
Cambridge CB3 0FD

Phone: +44-223-763500
Fax: +44-223-334748


Tobias Nipkow
Institut für Informatik
Technische Universität München
Boltzmannstr. 3
D-85748 Garching

Phone: +49-89-289-17302
Fax: +49-89-289-17307

Please report any problems you encounter. While we shall try to be helpful, we can accept no responsibility for the deficiencies of Isabelle and their consequences.