We are happy to announce the availability of 'xgrab' (X graph browser) a graph layout and browser package running under X11.R4. Xgrab reads a textual specification of a graph, lays out the graph using heuristics to minimize the number of edge crossings, and displays the graph as labeled nodes and edges in an X window. The user can then edit the graph. Once happy with the graph layout, xgrab can write a postscript file or a text file describing the resulting graph. Xgrab has been used to layout finite state machines, program dependence graphs, pert charts, trees, and much more. It works well for graphs with fewer than 30 nodes, but will work "adequately" for graphs with many more nodes. Xgrab is distributed using standard conventions for anonymous binary ftp of the compressed tar file 'pub/xgrab.tar.Z' from the machine 'cs.washington.edu'. If you take a copy of xgrab, please send mail to 'xgrab@cs.washington.edu' acknowledging that you have taken the software. THERE IS NO SUPPORT. In order to make xgrab run, you will also need version 2.6 of Mark Linton's Interviews software. If you do not already have this software you will need to use anonymous binary ftp of the compressed tar file '2.6.tar.Z' from the machine 'interviews.stanford.edu', and follow the directions contained therein. In addition, you will also need the latest release of the GNU C++ compiler "g++". If you do not already have this, you should grab the compressed tar file '2.6-and-g++.tar.Z' from 'interviews.stanford.edu'. It is unlikely that xgrab will work with AT&T CC. The xgrab software comes with a general purpose garbage collecting storage allocator written by Hans Boehm at Rice [Boehm et al 1988]. Xgrab has been compiled and successfully executed on vax/ultrix, running X11.R4. It was developed under sun/3, and should continue to run fine on that platform. Other platforms have not been tested, but the belief is that the software can port to other platforms that have g++, interviews and X11.R4. If g++ and interviews are not already installed at your site, then it will take a UNIX whiz about 1 day to read the documentation supplied with that software, figure out how to configure and then build the required software. The garbage collector will not run under decstation/ultrix because it has not yet been ported to that platform. In that event, xgrab can be compiled so that it does not recycle any storage. The layout algorithms used in xgrab were derived from algorithms by Sugiyama et al in 1981 [Sugiyama et al 1981]. The basis for the xgrab implementation was originally done by Rowe, Davis, Messinger, Meyer, Spirakis and Tuan [Rowe et al 1987] at the University of California, Berkeley, in a graph browser called 'sungrab' running under SunView. This code was then modified by Greg Barnes while employed as a summer intern at Tera Computer, Seattle, WA. Gregory S. Barnes, greg@cs.washington.edu Robert R. Henry, rrh@cs.washington.edu Computer Science and Engineering Department, FR-35 University of Washington Seattle, WA 98195 USA 206 685 1934 --------------------------------------------------------------------------- The Regents of the University of California is making this software available on a non commercial basis in order to facilitate its release. The Regents of the University of California hold the copyright on portions of the code, and state: GRAB Graph Layout and Browser System Copyright (c) 1986, 1988 Regents of the University of California Permission to use, copy, modify, and distribute this software and its documentation for educational, research, and non-profit purposes and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of the University of California not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. Permission to incorporate this software into commercial products can be obtained from the Campus Software Office, University of California, Berkeley, CA 94720. The University of California makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. --------------------------------------------------------------------------- Tera Computer is making this software available on a non commercial basis in order to facilitate its release. Tera holds the copyright on portions of the code, and states: Copyright (c) 1989, Tera Computer Company Permission to use, copy, modify and distribute this software and its documentation for educational, research and non-profit purposes and without fee is hereby granted, subject only to the condition that Tera Computer Company makes no representation about the suitability of this software for any purpose. It is provided "as is" without express or implicit warranty. --------------------------------------------------------------------------- Citations: [Boehm et al 1988] Boehm, H., and M. Weiser, "Garbage Collection in an Uncooperative Environment", Software Practice & Experience, September 1988, pp. 807-820. [Rowe et al 1987] L. A. Rowe, M. Davis, E. Messinger, C. Meyer, C. Spirakis and A. Tuan. "A Browser for Directed Graphs" , Software Practice & Experience, Volume 17, #1, January 1987. 61-76. [Sugiyama et al 1981] K. Sugiyama, S. Tagawa and M. Toda. "Methods for Visual Understanding of Hierarchical System Structures", IEEE Transactions on Systems, Man and Cybernetics, Volume 11, February 1981. 109-125.