This is the beta release of a OWL mode for the Emacs editor, based on a similar mode developed for DAML+OIL, the precursor language developed in DARPA's DAML Program. For more information about the DAML Program see The DAML Program Web Site.

For more information about OWL see The W3C Semantic Web Activity.

Software Requirements

This current release is was developed for XEmacs version 21.1, but will also work with GNU Emacs (versions from 19.28 up). It has been tested with GNU version 20, and works acceptably there, as long as you have a recent version of the W3 package for Emacs.

We recommend using OWL mode with XEmacs rather than GNU Emacs. It is faster and the fonts are much better. The W3 mode version mentioned above works with XEmacs as well, although the version available from is also fine.

If you need/want to install XEmacs on a windows platform, there are two installation sets for version 21.4.3 available at, and they are also downloadable from here:

When you install either of these, and try to run it for the first time, it will try to create an init file based on your prior GNU ~/.emacs file if one exits. You can avoid some confusion here by first creating the ~/.xemacs/init.el file with nothing in it, and then moving things over from your .emacs initialization file gradually.

OWL mode requires the Emacs W3 package to access web pages. The W3 mode version 4.0 installation tar is available from the University of Indiana at:
Download W3 mode.
After unpacking it, see the file INSTALL for a installation on UNIX or the README.NT for windows installation.

Installing OWL Mode

The 9/26/2003 beta release source code for OWL mode is downloadable from this tar file:

  1. Unpack the files into a directory named owl/ somewhere, such as ~/emacs/owl
  2. Edit your ~/.emacs (GNU or UNIX XEmacs) or ~/.xemacs/init.el (windows XEmacs) initialization file so that OWL Mode source code will be loaded, and the W3 mode is accessible.
  3. (optional) Compile the .el files in this directory. This seems to make the most difference for GNU emacs. To do it, in emacs do the following commands:
    1. M-x eval-expression <cr>
      at the prompt type: (setq in-xemacs-p t) if using XEmacs or (setq in-xemacs-p nil) if using GNU Emacs.
    2. M-x cd (at the prompt enter the code directory, e.g. "~/emacs/owl")
    3. M-x load-file (at the prompt enter "docomp")
To fix the load path (2 above), add the following two lines to the initialization file:

(setq load-path (append '("--path to the emacs code directory--/owl/" "--path to w3 directory--") load-path))
(autoload 'owl-mode "owl-mode" "OWL mode." t)
(push (cons "\\.owl" 'owl-mode) auto-mode-alist)

See the Readme for more details. The w3 path is needed only if installing it yourself for use with GNU Emacs.

Using OWL Mode

See the README with the distribution for more details.

Once OWL mode is installed, just open or create a file with extension .owl or edit any file and do


If you open a non-existent file, like "newfile.owl", some default header information plus the rdf:RDF and /rdf:RDF tags are inserted. See 'owl-helper-new-buffer-template' in the file owl-mode.el to change what this looks like.

To get full use OWL-MODE, you will have to ascertain that the W3 package is installed on your machine, and that the load path makes it accessible. With XEmacs, it often comes pre-installed. If it is not installed, you will not be able to use M-. to find OWL definitions on the web, but it will otherwise work fine.

To see if it is installed do

M-x locate-library (ENTER) w3 (ENTER)

If already installed, you will probably find it as a subdirectory under the XEmacs installation directory called

If you can't find it, you will have to install it. A copy of the tar'd (and gzipped) source for this package is available from but is also downloadable from directly here.

This package will occasionally be updated, as bugs are discovered. Copies of each of the individual .el files will be stored in the patch directory. as they change so that individual files can be retrieved instead of a full distribution.

Questions? Comments? Bugs?

Email to

This software is distributed AS IS and without Warranty.
Copyright BBN Technologies 2001-2003.

Mark Burstein
BBN Technologies
10 Moulton St.
Cambridge, MA 02138
Tel: 617-873-3861