GNU

GNU Software Online Documentation
DJGPP homepage

Hardware

Tom's Hardware Guide
Ars Technica

Linux

The Linux Documentation Project Home Page
XFree86(TM): Home Page
Scilab Home Page

Java

Documentation: Java(tm) and JavaSoft Products

Windows Programming

Borland Online
Borland C++ 5.5 Info
Microsoft Developers Network
Cygnus C/C++ compiler for win32

Real Time operating systems and embedded systems

VxWorks
QNX