Leonard "Len" H. Tower Jr. (born June 17, 1949) is a free softwareactivist and one of the founding board members of the Free Software Foundation,[1] where he contributed to the initial releases of gcc[2] and GNU diff. He left the Free Software Foundation in 1997.[3]
As the FSF's first full-time paid employee, Tower mostly performed administrative tasks, including managing mailing lists, newsgroups and requests for information.[6][7][8]
In 1986, Tower assisted Richard Stallman with Stallman's initial plan to base the C compiler for the GNU Project on the Pastel compiler Stallman had obtained from Lawrence Livermore Lab.[9] Tower worked on rewriting the existing code from Pastel, a variation of Pascal, into C[1] while Stallman worked on building the new C front end. Stallman dropped that plan when he discovered the Livermore compiler required too much memory, concluding, "I would have to write a new compiler from scratch. That new compiler is now known as GCC; none of the Pastel compiler is used in it, but I managed to adapt and use the C front end that I had written."[9] Stallman released his new GNU C compiler March 22, 1987,[10] acknowledging others' contributions, including Tower's, who "wrote parts of the parser, RTL generator, RTL definitions, and of the Vax machine description" based on ideas contributed by Jack Davidson and Christopher Fraser.[2][11]
Along with Mike Haertel,[12] David Hayes[13] and Stallman, Tower was also one of the initial co-authors of GNU diff, a file comparison utility based on a published algorithm[14] by Eugene Myers.[15][16][17]
During the late 1980s and early 1990s, Tower spoke at USENIX conferences as a representative of the FSF.[18]
^ ab Puzo, Jerome E., ed. (February 1986). "Gnu's Zoo". GNU's Bulletin. Free Software Foundation. 1 (1). Retrieved 2007-08-11. First ... there's Richard Stallman. ... Secondly there's Leonard H. Tower, Gnu's teddy bear. Len is Gnu's first and so far only paid full time employee. Gnu's Hawk, Robert Chassell ... [and] Professor Hal Abelson and Professor Geral Sussman ... round out FSF's board of Directors ... Although I have a portable C and Pascal compiler, ... most of the compiler is written in Pastel, ... so it must all be rewritten into C. Len Tower, the sole full-time GNU staff person, is working on this, with one or two assistants.
^ ab Stallman, Richard M. (24 April 1988), (PDF), Internals of GNU CC, Free Software Foundation, Inc., p. 7, archived from the original (PDF) on 2 April 2012, retrieved October 3, 2011, The idea of using RTL and some of the optimization ideas came from the U. of Arizona Portable Optimizer, written by Jack Davidson and Christopher Fraser. ... Leonard Tower wrote parts of the parser, RTL generator, RTL definitions, and of the Vax machine description.
^ Heuer, Karl, ed. (July 1997). "GNU's Who". GNU's Bulletin. Free Software Foundation, Inc. 1 (23). Retrieved October 9, 2011. Carol Botteron, Robert J. Chassell, Tami Friedman, Peter H. Salus, and Len Tower Jr. have left the FSF. Tami continues to volunteer for GNU as our Administrivia Coordinator. We thank them for their hard work.
^"Award for free software kicks off 'One world, one net' conference". 28 October 1998. Retrieved 18 September 2011.
^The Tech MIT student newspaper masthead, 15 February 1972, page 4.
^ Goldstein, Stacey; Chassell, Robert J.; Tower, Jr., Leonard, eds. (February 1988). "GNU's Who". GNU's Bulletin. Free Software Foundation, Inc. 1 (4). Retrieved October 4, 2011. Richard Stallman continues to do countless tasks, including refining the C compiler, GDB, GNU Emacs, etc. ... Finally, Len Tower continues to handle electronic administrivia (mailing lists, information requests, and system mothering).
^ Tuttle, Jonathan P.; Chassell, Robert J.; Tower Jr., Len, eds. (January 1997). "GNU's Who". GNU's Bulletin. Free Software Foundation. 1 (22). Retrieved October 4, 2011. Volunteers Phil Nelson and Len Tower work on our Web site. Len also remains our online JOAT (jack-of-all-trades), for mailing lists, gnUSENET newsgroups, information requests, etc.
^ Rubin, Paul, ed. (June 1987). "GNU's Who". GNU's Bulletin. Free Software Foundation. 1 (3). Retrieved October 4, 2011. Richard Stallman ... is currently continuing to develop the GNU C compiler. Hackers Len Tower, Richard Mlynarik, and Paul Rubin are doing various pieces of volunteer work as their time permits it, and Jay Fenlason continues to work full time on the GNU assembler and libraries.
^ ab Stallman, Richard (September 20, 2011). "About the GNU Project". The GNU Project. Retrieved October 9, 2011. Hoping to avoid the need to write the whole compiler myself, I obtained the source code for the Pastel compiler, which was a multiplatform compiler developed at Lawrence Livermore Lab. It supported, and was written in, an extended version of Pascal, designed to be a system-programming language. I added a C front end, and began porting it to the Motorola 68000 computer. But I had to give that up when I discovered that the compiler needed many megabytes of stack space, and the available 68000 Unix system would only allow 64k. ... I concluded I would have to write a new compiler from scratch. That new compiler is now known as GCC; none of the Pastel compiler is used in it, but I managed to adapt and use the C front end that I had written.
^ Richard M. Stallman (forwarded by Leonard H. Tower Jr.) (March 22, 1987). "GNU C compiler beta test release". Newsgroup: comp.lang.c. Retrieved October 9, 2011. The GNU C compiler is now available for ftp from the file /u2/emacs/gcc.tar on prep.ai.mit.edu. This includes machine descriptions for vax and sun, 60 pages of documentation on writing machine descriptions ... the ANSI standard (Nov 86) C preprocessor and 30 pages of reference manual for it. This compiler compiles itself correctly on the 68020 and did so recently on the vax. It recently compiled Emacs correctly on the 68020, and has also compiled tex-in-C and Kyoto Common Lisp.
^Stallman, Richard M. (2001) "Contributors to GCC," in Using and Porting the GNU Compiler Collection (GCC) for gcc version 2.95 (Cambridge, Mass.: Free Software Foundation)
^Mike Haertel (November 12, 1988). "Re: Implications of recent virus (Trojan Horse) attack". Newsgroup: comp.unix.wizards. Retrieved October 4, 2011. I am a college student. Also the author of GNU grep, coauthor of GNU diff, and working on GNU sort
^ David S. Hayes (August 19, 1993). "Re: Shareware (My Experience)". Newsgroup: comp.sys.mac.apps. Retrieved October 5, 2011. I wrote some of the original code in the GNU "diff" program. (It has since been replaced by other code.)
^ Myers, Eigene W. (1986). "An O(ND) Difference Algorithm and Its Variations" (PDF). Algorithmica. 1 (2): 251–266. doi:10.1007/BF01840446. S2CID 6996809. Retrieved October 4, 2011.
^ Bob Page (November 19, 1989). "v89i217: rcs - revision control system, Part02/14". Newsgroup: comp.sources.amiga. Retrieved October 4, 2011. GNU DIFF was written by Mike Haertel, David Hayes, Richard Stallman and Len Tower.
^ "analyze.c", diffutils-2.7, Free Software Foundation, Inc., October 2, 1994, retrieved October 4, 2011, The basic algorithm is described in: "An O(ND) Difference Algorithm and its Variations", Eugene Myers, Algorithmica Vol. 1 No. 2, 1986, pp. 251-266; see especially section 4.2, which describes the variation used below."
^Tower, Leonard H., et al. (2001) "AUTHORS" file, revision 1.3, GNU diff and patch utilities (Cambridge, Mass.: Free Software Foundation)
^Smallwood, Kevin C. (30 December 1991) "Updated BOF Schedule for San Francisco USENIX Conference," comp.org.usenix USENET posting;
^MacPhee, Spike R. (November 1991). . Programming Freedom. League for Programming Freedom. 1 (1). Archived from the original on 2007-03-10. Retrieved October 4, 2011. I run the speaker bureau. Richard M. Stallman and Len Tower have done the bulk of our speaking engagements to date, but cannot be everywhere at once. Our cloning attempts, despite Richard's views on copying, have not yet succeeded. We would like more volunteers, with or without previous experience, to speak to people around the world and inform them about the software look-and-feel and patent issues.
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This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This biography of a living person relies too much on references to primary sources Please help by adding secondary or tertiary sources Contentious material about living persons that is unsourced or poorly sourced must be removed immediately especially if potentially libelous or harmful Find sources Leonard H Tower Jr news newspapers books scholar JSTOR October 2011 Learn how and when to remove this template message The topic of this article may not meet Wikipedia s notability guideline for biographies Please help to demonstrate the notability of the topic by citing reliable secondary sources that are independent of the topic and provide significant coverage of it beyond a mere trivial mention If notability cannot be shown the article is likely to be merged redirected or deleted Find sources Leonard H Tower Jr news newspapers books scholar JSTOR March 2019 Learn how and when to remove this template message This article is an autobiography or has been extensively edited by the subject or by someone connected to the subject It may need editing to conform to Wikipedia s neutral point of view policy There may be relevant discussion on the talk page June 2019 Learn how and when to remove this template message Learn how and when to remove this template message Leonard Len H Tower Jr born June 17 1949 is a free software activist and one of the founding board members of the Free Software Foundation 1 where he contributed to the initial releases of gcc 2 and GNU diff He left the Free Software Foundation in 1997 3 Leonard H Tower Jr Len Tower wearing League for Programming Freedom and No Smoking badges c 1996 Born 1949 06 17 June 17 1949 age 74 New York City U S Alma materMITOccupationFree software activistOrganizationsFree Software Foundation League for Programming Freedom Contents 1 Birth 2 Academic career 3 GNU project 4 League for Programming Freedom 5 References 6 External linksBirth EditTower was born June 17 1949 in Astoria Queens in New York City U S Academic career EditIn 1971 Tower received an SB in biology from the Massachusetts Institute of Technology 4 During that time he was business manager at The Tech the student newspaper 5 GNU project EditAs the FSF s first full time paid employee Tower mostly performed administrative tasks including managing mailing lists newsgroups and requests for information 6 7 8 In 1986 Tower assisted Richard Stallman with Stallman s initial plan to base the C compiler for the GNU Project on the Pastel compiler Stallman had obtained from Lawrence Livermore Lab 9 Tower worked on rewriting the existing code from Pastel a variation of Pascal into C 1 while Stallman worked on building the new C front end Stallman dropped that plan when he discovered the Livermore compiler required too much memory concluding I would have to write a new compiler from scratch That new compiler is now known as GCC none of the Pastel compiler is used in it but I managed to adapt and use the C front end that I had written 9 Stallman released his new GNU C compiler March 22 1987 10 acknowledging others contributions including Tower s who wrote parts of the parser RTL generator RTL definitions and of the Vax machine description based on ideas contributed by Jack Davidson and Christopher Fraser 2 11 Along with Mike Haertel 12 David Hayes 13 and Stallman Tower was also one of the initial co authors of GNU diff a file comparison utility based on a published algorithm 14 by Eugene Myers 15 16 17 During the late 1980s and early 1990s Tower spoke at USENIX conferences as a representative of the FSF 18 League for Programming Freedom EditTower was an early member of the League for Programming Freedom Through 1991 Tower was one of the organization s two most active speakers along with Richard Stallman 19 References Edit a b Puzo Jerome E ed February 1986 Gnu s Zoo GNU s Bulletin Free Software Foundation 1 1 Retrieved 2007 08 11 First there s Richard Stallman Secondly there s Leonard H Tower Gnu s teddy bear Len is Gnu s first and so far only paid full time employee Gnu s Hawk Robert Chassell and Professor Hal Abelson and Professor Geral Sussman round out FSF s board of Directors Although I have a portable C and Pascal compiler most of the compiler is written in Pastel so it must all be rewritten into C Len Tower the sole full time GNU staff person is working on this with one or two assistants a b Stallman Richard M 24 April 1988 Contributors to GNU CC PDF Internals of GNU CC Free Software Foundation Inc p 7 archived from the original PDF on 2 April 2012 retrieved October 3 2011 The idea of using RTL and some of the optimization ideas came from the U of Arizona Portable Optimizer written by Jack Davidson and Christopher Fraser Leonard Tower wrote parts of the parser RTL generator RTL definitions and of the Vax machine description Heuer Karl ed July 1997 GNU s Who GNU s Bulletin Free Software Foundation Inc 1 23 Retrieved October 9 2011 Carol Botteron Robert J Chassell Tami Friedman Peter H Salus and Len Tower Jr have left the FSF Tami continues to volunteer for GNU as our Administrivia Coordinator We thank them for their hard work Award for free software kicks off One world one net conference 28 October 1998 Retrieved 18 September 2011 The Tech MIT student newspaper masthead 15 February 1972 page 4 Goldstein Stacey Chassell Robert J Tower Jr Leonard eds February 1988 GNU s Who GNU s Bulletin Free Software Foundation Inc 1 4 Retrieved October 4 2011 Richard Stallman continues to do countless tasks including refining the C compiler GDB GNU Emacs etc Finally Len Tower continues to handle electronic administrivia mailing lists information requests and system mothering Tuttle Jonathan P Chassell Robert J Tower Jr Len eds January 1997 GNU s Who GNU s Bulletin Free Software Foundation 1 22 Retrieved October 4 2011 Volunteers Phil Nelson and Len Tower work on our Web site Len also remains our online JOAT jack of all trades for mailing lists gnUSENET newsgroups information requests etc Rubin Paul ed June 1987 GNU s Who GNU s Bulletin Free Software Foundation 1 3 Retrieved October 4 2011 Richard Stallman is currently continuing to develop the GNU C compiler Hackers Len Tower Richard Mlynarik and Paul Rubin are doing various pieces of volunteer work as their time permits it and Jay Fenlason continues to work full time on the GNU assembler and libraries a b Stallman Richard September 20 2011 About the GNU Project The GNU Project Retrieved October 9 2011 Hoping to avoid the need to write the whole compiler myself I obtained the source code for the Pastel compiler which was a multiplatform compiler developed at Lawrence Livermore Lab It supported and was written in an extended version of Pascal designed to be a system programming language I added a C front end and began porting it to the Motorola 68000 computer But I had to give that up when I discovered that the compiler needed many megabytes of stack space and the available 68000 Unix system would only allow 64k I concluded I would have to write a new compiler from scratch That new compiler is now known as GCC none of the Pastel compiler is used in it but I managed to adapt and use the C front end that I had written Richard M Stallman forwarded by Leonard H Tower Jr March 22 1987 GNU C compiler beta test release Newsgroup comp lang c Retrieved October 9 2011 The GNU C compiler is now available for ftp from the file u2 emacs gcc tar on prep ai mit edu This includes machine descriptions for vax and sun 60 pages of documentation on writing machine descriptions the ANSI standard Nov 86 C preprocessor and 30 pages of reference manual for it This compiler compiles itself correctly on the 68020 and did so recently on the vax It recently compiled Emacs correctly on the 68020 and has also compiled tex in C and Kyoto Common Lisp Stallman Richard M 2001 Contributors to GCC in Using and Porting the GNU Compiler Collection GCC for gcc version 2 95 Cambridge Mass Free Software Foundation Mike Haertel November 12 1988 Re Implications of recent virus Trojan Horse attack Newsgroup comp unix wizards Retrieved October 4 2011 I am a college student Also the author of GNU grep coauthor of GNU diff and working on GNU sort David S Hayes August 19 1993 Re Shareware My Experience Newsgroup comp sys mac apps Retrieved October 5 2011 I wrote some of the original code in the GNU diff program It has since been replaced by other code Myers Eigene W 1986 An O ND Difference Algorithm and Its Variations PDF Algorithmica 1 2 251 266 doi 10 1007 BF01840446 S2CID 6996809 Retrieved October 4 2011 Bob Page November 19 1989 v89i217 rcs revision control system Part02 14 Newsgroup comp sources amiga Retrieved October 4 2011 GNU DIFF was written by Mike Haertel David Hayes Richard Stallman and Len Tower analyze c diffutils 2 7 Free Software Foundation Inc October 2 1994 retrieved October 4 2011 The basic algorithm is described in An O ND Difference Algorithm and its Variations Eugene Myers Algorithmica Vol 1 No 2 1986 pp 251 266 see especially section 4 2 which describes the variation used below Tower Leonard H et al 2001 AUTHORS file revision 1 3 GNU diff and patch utilities Cambridge Mass Free Software Foundation Smallwood Kevin C 30 December 1991 Updated BOF Schedule for San Francisco USENIX Conference comp org usenix USENET posting MacPhee Spike R November 1991 Speaking Volunteers Programming Freedom League for Programming Freedom 1 1 Archived from the original on 2007 03 10 Retrieved October 4 2011 I run the speaker bureau Richard M Stallman and Len Tower have done the bulk of our speaking engagements to date but cannot be everywhere at once Our cloning attempts despite Richard s views on copying have not yet succeeded We would like more volunteers with or without previous experience to speak to people around the world and inform them about the software look and feel and patent issues External links EditStudio pages at Art Net Website at the Massachusetts Institute of Technology Retrieved from https en wikipedia org w index php title Leonard H Tower Jr amp oldid 1171606810, wikipedia, wiki, book, books, library,
