About This Guide

The System Architecture guide accompanies the QNX realtime operating system and is intended for both application developers and end-users.

The guide describes the philosophy of QNX and the architecture used to robustly implement the OS. It covers message-passing services, followed by the details of the Neutrino microkernel, the process manager, resource managers, the Photon microGUI, and other aspects of QNX.

Note that certain features of the OS as described in this guide may still be under development for a given release.

For the latest news and information on QNX, visit the QNX Developer's Network (qdn.qnx.com). You'll find links to many useful areas -- software downloads, a searchable knowledge base, featured articles by developers, newsgroups, technical support options, and more.

The following table may help you find information quickly:

To find out about:	Go to:
OS design goals; message-passing IPC	The Philosophy of QNX
Microkernel services	The Neutrino Microkernel
Microkernel instrumentation	The Instrumented Microkernel
SMP systems	SMP with QNX
Process and memory management	Process Manager
Linking shared objects	Dynamic Linking
Resource managers (device drivers)	Resource Managers
Filesystems (image, RAM, QNX 4, DOS, CD-ROM, Flash, NFS, CIFS, Ext2)	Filesystems
Serial and parallel devices	Character I/O
Graphical environment	The Photon microGUI
Network subsystem	Networking Architecture
Native QNX networking (Qnet)	Qnet Networking
TCP/IP implementation	TCP/IP Networking
Fault recovery	High Availability Manager
List of functions in the QNX library	The QNX Library
Terms used in QNX docs	Glossary

Note to Windows users

In QNX documentation, we use a forward slash (/) as a delimiter in all pathnames, including those pointing to Windows files.

We also generally follow POSIX/UNIX filesystem conventions.