He created and maintains PuTTY, a free software implementation of Secure Shell (SSH) and Telnet for Microsoft Windows and Unix, along with an xterm terminal emulator.

He is also the original author of Netwide Assembler (NASM),[2] and maintains a collection of small computer programs which implement one-player puzzle games.

All of them run natively on Nintendo DS, Symbian S60, Unix (GTK; Android, MacOS), and Windows.

This article about an engineer, inventor or industrial designer from England is a stub.

You can help Wikipedia by expanding it.This article on a computer specialist of the United Kingdom is a stub.