Simon Tatham's Home Page

Welcome to my web site. I'm Simon Tatham, a software engineer and free-software author in Cambridge, UK.

Here are links to the various other pages of this site.

• About me: some idea of who I am.
• Free software I've written, which you can download.
  • PuTTY: a Telnet and SSH client for Windows.
  • Halibut: a half-written documentation system which is used for the PuTTY manual.
  • DoIt: a utility to allow a Unix machine to open documents on a Windows machine (for example, sending commands back to your Windows desktop machine from a Unix server you've connected to from there).
  • WinURL: a Windows utility to pull text out of the clipboard and launch it as a URL at the touch of a hot-key.
  • Enigma: a block-pushing puzzle game. Originally invented by a friend; converted to a curses-based Unix game by me.
  • A collection of GUI puzzle games, portable to many platforms: provided on the web in Javascript and Java versions, downloadable versions for Windows, Unix and MacOS, and third-party ports to various mobile devices.
  • Tweak: a Unix curses-based hex editor designed for highly scalable performance.
  • IPBT: a Unix curses application which plays back ttyrec files with precision rewind capability.
  • A collection of miscellaneous Unix utilities.
  • agedu: a Unix utility for tracking down where you're wasting disk space, by making it easy to spot large amounts of data with last-access times a long time ago.
  • xtruss: an X11 protocol tracing utility.
  • spigot: a command-line exact real calculator.
  • Bitmap fonts and font utilities for Windows.
  • Gonville, an alternative font of musical symbols for use with GNU Lilypond.
  • A set of scripts to fake the obsolete HTML <keygen> element, for the sake of websites that still require it even though modern browsers have withdrawn it.
  • A patch to bash(1) that implements a third mode of job termination notification.
  • ick-proxy, a disgusting utility for rewriting URLs in multiple web browsers.
• My algorithms collection: some neat algorithms that aren't in common use.
• Mathematical sorts of things. (Many of these pages include some downloadable software so you can play with them yourself.)
  • Filigrams: a kind of mathematical pretty picture, slightly similar to fractals but not exactly the same.
  • Newton-Raphson fractals.
  • Construction of polyhedra from mutually repelling points on a sphere.
  • Some pictures I've drawn on the surfaces of polyhedra, with downloadable nets so you can make your own copy.
  • A pair of dice which never roll 7.
  • A solution to the impossible Solitaire Army problem (by cheating, of course – making an infinite number of moves).
  • A few HTML5 web toys demonstrating mathematical things:
    • Lagrange's polynomial interpolation formula
    • the Gauss-Lucas theorem
    • the fractal you get by plotting all roots of complex polynomials with coefficients in a finite set
• Articles, essays and things I've written.
  • How to Report Bugs Effectively: a general article on how to send a programmer a bug report which will actually help them fix the problem.
  • Coroutines in C: an implementation of Knuth's "coroutines" concept in portable ANSI C, by a similar technique to Duff's device plus some C preprocessor abuse.
  • Metaprogramming custom control structures in C: another piece of C preprocessor abuse to let you build quite general user-defined looping constructs alongside C's basic for and while.
  • Magic Aliases: a dirty trick you can do by combining aliases and shell functions in the Bourne shell.
  • The Descent to C: an introduction to C for people coming to it from higher-level languages, intended to warn you in advance about the likely culture shocks.
  • My personal FAQ about the fact that I have no sense of smell.
  • Some more assorted articles organised into a kind of quasi-blog.