The Isabelle System Distribution

Version information

This is Isabelle98 as of January 1998. Compared to the Isabelle94 line it introduces many new features, but also some imcompatibilities. See the NEWS file in the distribution for more details.

System requirements

Isabelle requires a real Unix box with sufficient resources. Fun starts at about 32MB of memory (somewhat depending on your ML system), with several tens of MB disk space and a relatively fast CPU.

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

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

Poly/ML is a commercial product and costs money, but it is stable and efficient. It requires relatively little memory (starting at about 16MB) and disk space (about 40MB for all distributed object logics).

SML/NJ needs lots of store and disk space, but it is free. The current official release is 110. We also still support the old 0.93 release and working versions 109.27 to 109.33. Support for the 109 line of SML/NJ will be dropped next time! There is an unofficial pre-built binary distribution of SML/NJ 110 for Linux.


See file INSTALL in the Isabelle sources on how to build the system. Further background information may be found in the Isabelle System Manual, distributed as dvi with the sources.


The distribution includes only a very primitive interface based on ordinary terminal sessions.

David Aspinall has written a more elaborate user interface for Isabelle. It runs under recent versions of GNU Emacs and XEmacs, the latter being recommended. It's useful to both novices and experts.

Other sources of information

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
Pembroke Street
Cambridge CB2 3QG

Phone: +44-223-334600
Fax: +44-223-334748


Tobias Nipkow
Institut fuer Informatik
T. U. Muenchen
D-80290 Muenchen

Phone: +49-89-289-22690
Fax: +49-89-289-28183

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