Jan Wolter
Contract Software Design and Programming

• Design and Implementation of Complex Distributed Systems.
• Unix Programming in C and Perl.
• CGI and JavaScript Programs for Web Sites.
• Secure Web Authentication Systems.
• SQL Databases.
• Java and J2EE Server Applications.
• Templating Systems.
• Custom Internet Client and Server Software.
• Computer Conferencing Systems and other Communications Tools.
• Custom Unix System Administration Tools.
• Unix Software Portability.
• Customization of Third-Party Software.
• Pickup of Partially Completed Projects.
• Artificial Intelligence Systems.
• Writing Technical Documentation.
• Technical Team Leadership.

And most of all, not forgetting what the business is about: listening to the customer, finding sensible solutions that fit their needs and budget, looking for ways to make things better, communicating what I am doing and why I am doing it, and getting the job done well and quickly.

I have a Ph.D. in Computer Engineers, and have been programming for almost forty years, for fun and profit, working in a wide variety of languages and environments and a wide variety of applications areas. I have the depth of experience to handle most any kind of programming task.

• Professional Graphics Design.
• Professional Copy Writing.
• Permanent, Full-time Employment.
• Porn Sites.
• Windows.

I often work independently, but am also associated with a couple larger web development companies. The Factotem Constellation is an affliation of freelance developers. Working with this organization, I can assemble complete, top quality, multinational development teams, including professional project managers, graphics designers, technical writers, and even Windows programmers.

Significant Software Projects

• Politaire - 2013-present - A just-for-fun Javascript Solitaire game that plays any of hundreds of different solitaire environments. This was an experiment in building a dynamic site that runs entirely on the client side, loading only static files from the server. The site is far more complex than it at first appears. It dynamnically reformats to screen size, and all game rules can be modified by the player so that all 500+ games are really the same game with different settings. Documentation is automatically generated from current rules settings, so new manual pages do not need to be written for new games. As a side project, I built fast solvers for various solitaire games, to generate statistics on the solvability of games and study the impact of shuffling styles on game play.

• EMPA Data Collection and Report Generation - 2005-present - Developed database-based system for collecting results from large on-line surveys and reporting results. Includes web-based query generation tool, real-time graph and PDF generation, and lots of Javascript, etc. This is a Factotem Project.

• ANX Tunnelz - 2003-2004 - Working for Logic Solutions on supporting and enhancing a tool to manage a virtual private network for the auto industry. Project involved Java in a J2EE server environment, JSP, Perl, and various open source packages including JBoss, Big Brother, Cricket, NetSNMP, MySQL and RDDTool.

• Web Paint-by-Number - 2002-present - A just-for-fun website that allows users to create and solve graphical logic puzzles. Some very fancy JavaScript with some fairly ordinary Perl and MySQL code generating it. Heavy use of AJAX techniques. Includes discussion forums, a simple chat function, and a sophisticated AI puzzle solver written in C. SVG rendering is an option.

• MaintenanceLogs.com - 2002-2003 - MaintenanceLogs.com was originally implemented by another programmer, who left the job when it was partially complete. I finished the job, making substantial improvements to the design and security. Have done lots of fancy JavaScript here. Site design is by Keystone Media.

• Horizon Telemetry - 2002-2003 - A derivative of the Eberwhite software system (described below) targetted toward remotely collecting usage and fault data from leased fork lift trucks.

• RISEE - 2000-2003 - A database of environmental educational resources and events. Heavily templated system provides different look-and-feel interfaces for several dozen different organizations including the Colorado Alliance for Environmental Education, Pennsylvania Center for Environmental Education, Biodiversity Education Network and ThinkEarth. Allows calendar events to be shared between organizations, and provides a rich set of administrative tools at all levels.

• EMPA Surveys - 2001 - Developed a set of CGI scripts that were integrated with a front end written in Flash by Mark Lebay to collect results from employee surveys. This is a Factotem Project. Occasionally Mark and I create new versions for different surveys, so this has been a low-level ungoing project through 2005.

• Eberwhite - 2000-2001 - Implemented a system for collecting, storing, and reporting data on levels of various chemicals in remote storage tanks.
  • Designed and implemented network interface to Cellemetry cellular data network, with custom protocol, for programming and data retrieval from remote units. This work lead to a patent.
  • Implemented templated web site with authentication and real-time data graph generation on top of an Oracle database.
  • Design and implementation of hierarchical JavaScript naviagation system.

• Booktalk - 2000-2001 - Booktalk is a kid-friendly conferencing system developed on top of my Backtalk conferencing system. It was developed for the Canton Public Library for use by students and teachers of the Canton Public schools.

• I-Gift - 1999 - Lead engineer with Factotem designing a fulfillment system for a custom gift certificate printing operation.
  • Designed a flexible, rapidly-scalable fulfillment operation based on distributed printing cells assigned jobs by a central fulfillment server.
  • Developed http protocols for communication between fulfillment server and web store, and between Java-driven cells and fulfillment server.
  • Implemented fulfillment server in Perl on top of a Sybase database including polling web store as http client, job scheduling for cells, and advanced system administration and monitoring screens.
  • Implemented interfaces to UPS on-line tools for rate computation and shipping manifest generation.

• SimpleRate - 1998 - Programmer with Factotem for a site reselling long distance services on-line. (Now defunct.)
  • Developed a sophisticated Perl templating system allowing affinity groups to rebrand and customize the look of the site.
  • Tools to import rate tables and suggest most appropriate service to customers.
  • Customer E-mail address confirmation using procmail.
  • Various http client interfaces to pass orders to long distance companies.
  • Document editing system to allow copy writers to put information on site without writing HTML.
  • Session-based authentication system.

• Ford Virtual Tool Set - 1997 - Programmer for Logic Solutions on a project to do sheet metal stamping simulation in a web environment for Ford Motor Company. My responsibility was developing software to distribute simulation jobs (which could run for days) from the central server to execution machines, and to retrieve final and intermediate data for viewing on the web. Communications protocols were based on E-mail and ftp. Database was initially WAIS (bad idea) and later Oracle.

• Backtalk - 1996-2007 - Backtalk is an excessively sophisticated free web conferencing package written in C. Generates web pages using on a PostScript-like script interpreter. Very portable.

• Mod_auth_extern and Pwauth - 1996-present - Mod_auth_extern is a freeware Apache module for authentication originally written by Nathan Neulinger modified and supported by me. Pwauth is a program I developed that, with mod_auth_extern, allows secure web authentication from a Unix shadow password database or any PAM server.

• Grex Administration Tools - 1995-2007 - Grex is a non-profit, public access computer conferencing system with 25,000 users on a Sun 4/670 that I do volunteer work for. Software developed for use there consists mainly of tools to help a small volunteer staff to administer a system where over 200 new accounts are created every day.
  • web-newuser, a web-interface for instant creation of new Unix accounts.
  • Robocop, a daemon that monitors the system for orphaned processes, fork bombs, and memory bombs and agressively kills them.
  • Repass, a web-based system allowing users who have forgotten their passwords to pass certain security checks and request that the password on the account be automatically reset to a random value and mailed to an off-site email address.
  • Reap, a program that identifies unused accounts and schedules them for deletion.
  • Zapuser, a program that actually deletes accounts, handling various nasty conditions including arbitrarily deeply nested subdirectories, race conditions with symbolic links, etc. Logs and optionally backs up all data.
  I've also developed web interfaces for resetting Unix shadow passwords for other public access systems.

• Orville Write - 1983-2004 - Orville Write is a freeware reimplementation of the Unix write command with many advanced features.

• Party - 1985-1999 - Party is a freeware command-line chat system dating back to before such things were ordinary.

• Artificial Intelligence Systems - 1985-1995 - In the context of academic research, I've built a number of AI planning systems with a strong geometrical reasoning emphasis for solving problems in Robotics, Oil Spill Clean-Up, Computer-Aided Design, and Computer-Aided Manufacture. Published many academic papers based on this work.

• Geometric Modelling Systems - 1983-1995 - Lots of experience designing and implementing geometric modeling systems and doing computational geometry. Published several academic papers based on this work.

• Data Acquisition Libraries - 1980 - As a programmer for Hewlett Packard, wrote data acquisition library code for controlling various electronic instruments over an IEEE-488 interface. Code was written in HPL for the HP9825 computer.

• A Guide to Web Authentication Alternatives - Overview of methods for doing authentication for web sites.

• Javascript Madness - Studies software portability issues in Javascript, especially relating to mouse and keyboard events.

• Unix Incompatibility Notes - Studies of some Unix software portability issues.

• Survey of Paint-by-Number Puzzle Solvers - Detailed comparision and analysis of various AI programs for solving a class of Japanese logic puzzles also known as nonograms.

• Grex Staff Notes - Documentation of Grex's software and operations for the interested reader.

• A Partial History of Computer Conferencing in Ann Arbor.

• Operating Systems: Most common versions of Unix, including OS X, Linux, FreeBSD, OpenBSD, Solaris, SunOS, AIX, IRIX, Mac OS X, Mach.

• Programming Languages: Extremely experienced with C, Perl and JavaScript. Also Java, C++, PostScript. Have done work in dozens of other languages (including 370 assembler, Ada, APL, Basic, Fortran, Forth, HPL, Lisp, Pascal, Prolog, PL/I, and Z-80 Assembler) and can pick new ones up readily.

• Database Packages: Oracle, PostgreSQL, MySQL, Sybase, Msql. Most Unix DB packages. WAIS. Perl, Java and C interfaces to most of the above.

• Apache HTTP Server: configuration and custom module development.

• Miscellaneous: CVS, subversion, Gnu autoconf, various regular expression libraries, procmail, PAM, lots more.

Availability