Introduction to Unix

An Introduction to Linux
Last updated: January 29, 2015 at 08:00
&

Credits
Cleveland Linux Users’ Group
Introduction to Linux (Jeff Gilton & Jim Weirich)
IBM
An Introduction to Linux (Al Henderson)
Why Linux is storming the market (Jonathan Prial)
Ivan Bowman
Conceptual software architecture of the Linux kernel

Contents
A quick guide to Linux
Background
Using Linux
S/390 Specifics
Linux in the Marketplace
Commercial Linux Applications
Additional Resources

What is Linux
A fully-networked 32/64-Bit Unix-like Operating System
Unix Tools Like sed, awk, and grep (explained later)
Compilers Like C, C++, Fortran, Smalltalk, Ada
Network Tools Like telnet, ftp, ping, traceroute
Multi-user, Multitasking, Multiprocessor
Has the X Windows GUI
Coexists with other Operating Systems
Runs on multiple platforms
Includes the Source Code

Where did it come from?
Linus Torvalds created it
with assistance from programmers around the
world
first posted on Internet in 1991
Linux 1.0 in 1994; 2.2 in 1999
Today used on 7-10 million computers
with 1000’s of programmers working to
enhance it

Open Source Software
When programmers on the Internet can
read, redistribute, and modify the source
for a piece of software, it evolves
People improve it, people adapt it, people
fix bugs. And this can happen at a speed
that, compared to conventional software
development, seems astonishing

How do you get it?
Download it from the Internet
From a “Distribution” (e.g. RedHat)
Linux kernel
X Windows system and GUI
Web, e-mail, FTP servers
Installation & configuration support
3rd party apps
Hardware support

Why is it significant?
Growing popularity
Powerful
Runs on multiple hardware platforms
Users like its speed and stability
No requirement for latest hardware
It’s “free”
Licensed under GPL
Vendors are distributors who package Linux

Logging In
Connect to the Linux system using telnet:
vt100, vt220, vt320
ansi
tty
X-windows
Able to login more than once with same
user
No ‘MW’ problems!

Logging In
Before you can use it you must login by
specifying your account and password:
Linux 2.2.13 (penguinvm.princeton.edu) (ttyp1)
penguinvm login: neale
Password:
Last login: Tue Jan 4 10:13:13 from
linuxtcp.princeton.edu
[neale@penguinvm neale]$

Rule Number 1
Do not login as root unless you have to
root is the system superuser (the “maint” of
Linux but more “dangerous”)
Normal protection mechanisms can be overridden
Careless use can cause damage
Has access to everything by default
root is the only user defined when you install
First thing is to change root’s password
The second job is to define “normal” users for
everyday use

Creating a new user
Use the useradd command
Use the passwd command to set
password
Try it… logon as root[root@penguinvm]# useradd scully
[root@penguinvm]# passwd scully
Changing password for user scully
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated
successfully
[root@penguinvm]#

Adding a new user
Limits on users can be controlled by
Quotas
ulimit command
Authority levels for a user controlled by
group membership

Users and Groups
Users are identified by user identifications (UIDs), each
of which is associated with an integer in the range of 0
to 4 294 967 295 (X’FFFFFFFF’). Users with UID=0 are
given superuser privileges.
Users are placed in groups, identified by group
identifications (GIDs). Each GID is associated with an
integer in the range from 0 to 4 294 967 295
Let the system assign UID to avoid duplicates
Use id to display your user and group information
uid=500(neale) gid=500(neale) groups=500(neale),3(sys),4(adm)

Users and Groups
Groups define functional areas/responsibilities
They allow a collection of users to share files
A user can belong to multiple groups
You can see what groups you belong to using
the groups command:
neale sys adm

Typical Group Setup
sys
bin
adm
staff

Using the new user
Now logoff using the exit command
login as the new user
Linux 2.2.13 (penguinvm.princeton.edu) (ttyp2)
penguinvm login: scully
Password:
[scully@penguinvm scully]$

You need help?
The Linux equivalent of HELP is man
(manual)
Use man -k <keyword> to find all
commands with that keyword
Use man <command> to display help for that
command
Output is presented a page at a time. Use b for to
scroll backward, f or a space to scroll forward and
q to quit

The Linux System
User commands
Shell
File SystemsKernel
Device Drivers
Hardware
User commands includes executable
programs and scripts
The shell interprets user commands. It is
responsible for finding the commands
and starting their execution. Several
different shells are available. Bash is
popular,
The kernel manages the hardware resources
for the rest of the system.

Linux File System Basics
Linux files are stored
in a single rooted,
hierarchical file
system
Data files are stored
in directories (folders)
Directories may be
nested as deep as
needed
Directories
User home
directories
Data files
root

Naming Files
Files are named by
naming each
containing directory
starting at the root
This is known as the
pathname /etc/passwd
/home/neale/b

The Current Directory
One directory is
designated the
current working
directory
if you omit the
leading / then path
name is relative to the
current working
directory
Use pwd to find out
where you areCurrent
working
directory doc/letter
./doc/letter
/home/neale/doc/letter

Some Special File Names
Some file names are special:
/ The root directory (not to be confused with the root user)
. The current directory
.. The parent (previous) directory
~ My home directory
Examples:
./a same as a
../jane/x go up one level then look in directory jane for x

Special Files
/home - all users’ home directories are stored
here
/bin, /usr/bin - system commands
/sbin, /usr/sbin - commands used by
sysadmins
/etc - all sorts of configuration files
/var - logs, spool directories etc.
/dev - device files
/proc - special system files

Linux Command Basics
To execute a command, type its name
and arguments at the command line
ls -l /etc
Command name
Options
(flags)
Arguments

Standard Files
UNIX concept of “standard files”
standard input (where a command gets its
input) - default is the terminal
standard output (where a command writes it
output) - default is the terminal
standard error (where a command writes
error messages) - default is the terminal

Redirecting Output
The output of a command may be sent
(piped) to a file:
ls -l >output
“>” is used to specify
the output file

Redirecting Input
The input of a command may come (be
piped) from a file:
wc <input
“<” is used to specify
the input file

Connecting commands
with Pipes
Not as powerful as CMS Pipes but the
same principle
The output of one command can become
the input of another:
ps aux | grep netscape | wc -l
The output of the ps
command is sent to
grep
grep takes input and searches for
“netscape” passing these lines to wc
wc takes this input and
counts the lines its output
going to the console
Like CMS Pipes, “|” is
used to separate stages

Command Options
Command options allow you to control a
command to a certain degree
Conventions:
Usually being with a single dash and are a
single letter (“-l”)
Sometimes have double dashes followed by a
keyword (“--help”)
Sometimes follow no pattern at all

Common Commands
pwd - print (display) the working directory
cd <dir> - change the current working
directory to dir
ls - list the files in the current working directory
ls -l - list the files in the current working
directory in long format

File Commands
cp <fromfile> <tofile>
Copy from the <fromfile> to the <tofile>
mv <fromfile> <tofile>
Move/rename the <fromfile> to the <tofile>
rm <file>
Remove the file named <file>
mkdir <newdir>
Make a new directory called <newdir>
rmdir <dir>
Remove an (empty) directory

More Commands
who
List who is currently logged on to the system
whoami
Report what user you are logged on as
ps
List your processes on the system
ps aux
List all the processes on the system
echo “A string to be echoed”
Echo a string (or list of arguments) to the terminal

More Commands
alias - used to tailor commands:
alias erase=rm
alias grep=”grep -i”
ar - Maintain archive libraries: a
collection of files (usually object files
which may be linked to a program, like a
CMS TXTLIB)
ar -t libgdbm.a
__.SYMDEF
dbmopen.o

More Commands
awk - a file processing language that is
well suited to data manipulation and
retrieval of information from text files
chown - sets the user ID (UID) to owner
for the files and directories named by
pathname arguments. This command is
useful when from test to production
chown -R apache:httpd /usr/local/apache

More Commands
diff - attempts to determine the minimal
set of changes needed to convert a file
specified by the first argument into the file
specified by the second argument
find - Searches a given file hierarchy
specified by path, finding files that match
the criteria given by expression

More Commands
grep - Searches files for one or more
pattern arguments. It does plain string,
basic regular expression, and extended
regular expression searching
find ./ -name "*.c" | xargs grep -i "fork"
In this example, we look for files with an extension “c” (that is, C source files). The filenames we
find are passed to the xargs command which takes these names and constructs a command line
of the form: grep -i fork <file.1>…<file.n>. This command will search the files for the
occurrence of the string “fork”. The “-i” flag makes the search case insensitve.

More Commands
kill - sends a signal to a process or
process group
You can only kill your own processes
unless you are root
UID PID PPID C STIME TTY TIME CMD
root 6715 6692 2 14:34 ttyp0 00:00:00 sleep 10h
root 6716 6692 0 14:34 ttyp0 00:00:00 ps -ef
[root@penguinvm log]# kill 6715
[1]+ Terminated sleep 10h

More Commands
make - helps you manage projects
containing a set of interdependent files
(e.g. a program with many source and
object files; a document built from source
files; macro files)
make keeps all such files up to date with
one another: If one file changes, make
updates all the other files that depend on
the changed file
Roughly the equivalent of VMFBLD

More Commands
sed - applies a set of editing subcommands
contained in a script to each argument input
file
find ./ -name "*.c,v" | sed ’s/,v//g’ | xargs grep "PATH"
This finds all files in the current and subsequent directories with an extension of c,v. sed
then strips the ,v off the results of the find command. xargs then uses the results of sed
and builds a grep command which searches for occurrences of the word PATH in the C
source files.

More Commands
tar - manipulates archives
An archive is a single file that contains the
complete contents of a set of other files; an
archive preserves the directory hierarchy that
contained the original files. Similary to a
VMARC file
tar -tzf imap-4.7.tar.gz
imap-4.7/
imap-4.7/src/
imap-4.7/src/c-client/
imap-4.7/src/c-client/env.h
imap-4.7/src/c-client/fs.h

Shells
An interface between the Linux system
and the user
Used to call commands and programs
An interpreter
Powerful programming language
“Shell scripts” = .bat .cmd EXEC REXX
Many available (bsh; ksh; csh; bash; tcsh)

Another definition of a Shell
A shell is any program that takes input
from the user, translates it into instructions
that the operating system can understand,
and conveys the operating system's
output back to the user.
• i.e. Any User Interface
• Character Based v Graphics Based

Why Do I Care About
The Shell?
Shell is Not Integral Part of OS
UNIX Among First to Separate
Compare to MS-DOS, Mac, Win95, VM/CMS
GUI is NOT Required
Default Shell Can Be Configured
chsh -s /bin/bash
/etc/passwd
Helps To Customize Environment

#!/bin/bash
while
true
do
cat somefile > /dev/null
echo .
done
Shell Scripts
/* */
do forever
‘PIPE < SOME FILE | hole’
say ‘.’
end

Switching Users
su <accountname>
switch user accounts. You will be prompted for a
password. When this command completes, you will
be logged into the new account. Type exit to return
to the previous account
su
Switch to the root user account. Do not do this lightly
Note: The root user does not need to enter a password when
switching users. It may become any user desired. This is part of the
power of the root account.

Environment Variables
Environment variables are global settings
that control the function of the shell and
other Linux programs. They are sometimes
referred to global shell variables.
Setting:
VAR=/home/fred/doc
export TERM=ansi
SYSTEMNAME=`uname -n`
Similar to GLOBALV SET … in CMS

Using Environment Variables:
echo $VAR
cd $VAR
cd $HOME
echo “You are running on $SYSTEMNAME”
Displaying - use the following commands:
set (displays local & env. Vars)
export
Vars can be retrieved by a script or a program

Some Important
HOME
Your home directory (often be abbreviated as “~”)
TERM
The type of terminal you are running (for example
vt100, xterm, and ansi)
PWD
Current working directory
PATH
List of directories to search for commands

PATH Environment Variable
Controls where commands are found
PATH is a list of directory pathnames separated
by colons. For example:
PATH=/bin:/usr/bin:/usr/X11R6/bin:/u
sr/local/bin:/home/scully/bin
If a command does not contain a slash, the shell
tries finding the command in each directory in
PATH. The first match is the command that will
run

PATH Environment Variable
Similar to setting the CMS search order
Usually set in /etc/profile (like the
SYSPROF EXEC)
Often modified in ~/.profile (like the
PROFILE EXEC)

File Permissions
Every file
Is owned by someone
Belongs to a group
Has certain access permissions for owner,
group, and others
Default permissions determined by umask

File Permissions
Every user:
Has a uid (login name), gid (login group) and
membership of a "groups" list:
The uid is who you are (name and number)
The gid is your initial “login group” you normally
belong to
The groups list is the file groups you can access
via group permissions

File Permissions
Linux provides three kinds of permissions:
Read - users with read permission may read
the file or list the directory
Write - users with write permission may write
to the file or new files to the directory
Execute - users with execute permission may
execute the file or lookup a specific file within
a directory

File Permissions
The long version of a file listing (ls -l)
will display the file permissions:
-rwxrwxr-x 1 rvdheij rvdheij 5224 Dec 30 03:22 hello
-rw-rw-r-- 1 rvdheij rvdheij 221 Dec 30 03:59 hello.c
-rw-rw-r-- 1 rvdheij rvdheij 1514 Dec 30 03:59 hello.s
drwxrwxr-x 7 rvdheij rvdheij 1024 Dec 31 14:52 posixuft
Permissions
Owner
Group

Interpreting File Permissions
-rwxrwxrwx
Other permissions
Group permissions
Owner permissions
Directory flag (d=directory; l=link)

Changing File Permissions
Use the chmod command to change file
permissions
The permissions are encoded as an octal
number
chmod 755 file # Owner=rwx Group=r-x Other=r-x
chmod 500 file2 # Owner=r-x Group=--- Other=---
chmod 644 file3 # Owner=rw- Group=r-- Other=r--
chmod +x file # Add execute permission to file for all
chmod o-r file # Remove read permission for others
chmod a+w file # Add write permission for everyone

Links?
Links are references to files (aliases)
Two forms:
Hard
Symbolic
Can point to files on different physical devices
Delete of original leaves link
Delete of link leaves original
Can be created for directories
Create using ln command

Editors
People are fanatical about their editor
Several choices available:
vi Standard UNIX editor
the XEDIT-like editor
xedit X windows text editor
emacs Extensible, Customizable Self-
Documenting Display Editor
pico Simple display-oriented text editor
nedit X windows Motif text editor

Linux Device Handling
Devices are the way linux talks to the world
Devices are special files in the /dev
directory (try ls /dev)
/dev/ttyx TTY devices
/dev/hdb IDE hard drive
/dev/hdb1 Partition 1 on the IDE hard drive
/dev/mnda VM Minidisk
/dev/dda Channel Attached DASD
/dev/dda1 Partition 1 on DASD
/dev/null The null device (“hole”)
/dev/zero An endless stream of zeroes
/dev/mouse Link to mouse (not /390)

Devices and Drivers
Each /dev file has a major and minor
number
Major defines the device type
Minor defines device within that type
Drivers register a device type
brw-r--r-- 1 root root 64, 0 Jun 1 1999 /dev/mnda
crw-r--r-- 1 root root 5, 0 Jan 5 09:18 /dev/tty
Major no. Minor no.
Device Type:
b - block
c - character

Special Files - /proc
Information about internal Linux
processes are accessible to users via
the /proc file system (in memory)
/proc/cpuinfo CPU Information
/proc/interrupts Interrupt usage
/proc/version Kernel version
/proc/modules Active modules
cat /proc/cpuinfo
vendor_id : IBM/S390
# processors : 1
bogomips per cpu: 86.83
processor 0: version = FF, identification = 045226, machine = 9672

File Systems
Linux supports many different types
Most commonly, ext2fs
Filenames of 255 characters
File sizes up to 2GB
Theoretical limit 4TB
Derived from extfs
Highly reliable and high performer

File Systems
Other file systems:
sysv - SCO/Xenix
ufs - SunOS/BSD
vfat - Win9x
msdos - MS-
DOS/Win
umsdos- Linux/DOS
ntfs - WinNT (r/o)
hpfs - OS/2 (r/o)
Other File systems:
iso9660 (CD-ROM)
nfs - NFS
coda - NFS-like
ncp - Novell
smb - LANManager
etc

File Systems
mount
Mounts a file system that lives on a device to
the main file tree
Start at Root file system
Mount to root
Mount to points currently mounted to root
/etc/fstab used to establish boot time
mounting

Virtual File System
VFS is designed to present a consistent
view of data as stored on hardware
Almost all hardware devices are
represented using a generic interface
VFS goes further, allowing the sysadmin
to mount any of a set of logical file
systems on any physical device

Virtual File System
Logical file systems promote compatibility
with other operating system standards
permitting developers to implement file
systems with different policies
VFS abstracts details of physical device
and logical file system allowing processes
to access files using a common interface,
without knowing what physical or logical
system the file resides on

Virtual File System
Analogous to CMS:
SFS
Minidisks
Two different designs
Common/transparent access

Processes
Processes are created in a hierarchical structure whose
depth is limited only by the virtual memory available to
the virtual machine
A process may control the execution of any of its
descendants by suspending or resuming it, altering its
relative priority, or even terminating it
Termination of a process by default causes termination
of all its descendants; termination of the root process
causes termination of the session
Linux assigns a process ID (PID) to the process

Processes
Foreground
When a command is executed from the prompt and
runs to completion at which time the prompt returns is
said to run in the foreground
Background
When a command is executed from the prompt with
the token “&” at the end of the command line, the
prompt immediately returns while the command
continues is said to run in the background

Processes
Daemons
Background processes for system
administration are referred to as “daemons”
These processes are usually started during
the boot process
The processes are not assigned any
terminalsUID PID PPID C STIME TTY TIME CMD
root 5 1 0 1999 ? 00:00:14 [kswapd]
bin 254 1 0 1999 ? 00:00:00 [portmap]
root 307 1 0 1999 ? 00:00:23 syslogd -m 0
root 350 1 0 1999 ? 00:00:34 httpd

Processes
[root@penguinvm log]# sleep 10h &
[1] 6718
[root@penguinvm log]# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 6718 6692 0 14:49 ttyp0 00:00:00 sleep 10h
& causes process to be run
in “background”
Job Number Process ID (ID) Parent Process ID

Processes - UID & GID
Real UID
At process creation, the real UID identifies the
user who has created the process
Real GID
At process creation, the real GID identifies
the current connect group of the user for
which the process was created

Effective UID
The effective UID is used to determine owner access
privileges of a process.
Normally the same as the real UID. It is possible for a
program to have a special flag set that, when this
program is executed, changes the effective UID of
the process to the UID of the owner of the program.
A program with this special flag set is said to be a
set-user-ID program (SUID). This feature provides
additional permissions to users while the SUID
program is being executed.

Effective GID
Each process also has an effective group
The effective GID is used to determine group access
privileges of a process
Normally the same as the real GID. A program can
have a special flag set that, when this program is
executed, changes the effective GID of the process to
the GID of the owner of this program
A program with this special flag set is said to be a
set-group-ID program (SGID). Like the SUID feature,
this provides additional permission to users while the
set-group-ID program is being executed

Processes - Process Groups
Each process belongs to a process group
A process group is a collection of one or more
processes
Each process group has a unique process group ID
It is possible to send a signal to every process in the
group just by sending the signal to the process group
leader
Each time the shell creates a process to run an
application, the process is placed into a new process
group
When an application spawns new processes, these are
members of the same process group as the parent

Processes - PID
PID
A process ID is a unique identifier assigned to
a process while it runs
Each time you run a process, it has a different
PID (it takes a long time for a PID to be
reused by the system)
You can use the PID to track the status of a
process with the ps command or the jobs
command, or to end a process with the kill
command

Processes - PGID
PGID
Each process in a process group shares a
process group ID (PGID), which is the same
as the PID of the first process in the process
group
This ID is used for signaling-related
processes
If a command starts just one process, its PID
and PGID are the same

Processes - PPID
PPID
A process that creates a new process is
called a parent process; the new process is
called a child process
The parent process (PPID) becomes
associated with the new child process when it
is created
The PPID is not used for job control

Security Guidelines
Take Care With Passwords
Use good ones (motherhood statement)
Don't Use Real Words
Make Sure They Are Not Easily Guessed
Use Combinations Of Upper and Lower Case,
Numbers, Punctuation
One Method: Take first letter of a sentence or
book title, insert numbers and punctuation.

Security Guidelines
Take care of passwords (continued)
Use Shadow Passwords
Allows encrypted passwords to be in a file that is
not world readable
Use Password Aging
Requires shadow passwords

Security Guidelines
Restrict Superuser Access
Restrict where root can log in from
/etc/securetty restricts root access to devices
listed
Use wheel group to restrict who can su to
root
Put users who can su to root in wheel group in
/etc/group file.

Security Guidelines
Use groups to allow access to files that
must be shared
Otherwise users will set world permission
Be careful with SUID and SGID
Avoid setting executables to SUID root
Wrap SUID root wrapper around programs if
they must be run SUID root
Create special accounts for programs that
must run with higher permissions

Security - Important Files
/etc/passwd - password file
/etc/shpasswd - shadow password file
/etc/group -lists groups and users contained in groups
/etc/services - lists network services and their ports
/etc/ftpusers - contains list of accounts that cannot use ftp
/etc/hosts.equiv - generic list of remote users
~/.rhosts - list of remote users for a specific account
/etc/hosts - host definition list
/etc/hosts.lpd - hosts who can use remote printing
/etc/hosts.allow - lists services that remote users are allowed to use
/etc/hosts.deny - lists services tthat remote users are not allowed to use
/etc/nologin - no login message that also disables logins
/etc/securetty - lists legal terminals for root to login from
/etc/exports - lists locations that can be remotely accessed via NFS
/etc/syslog.conf - configures the syslog facility
/etc/inetd.conf - configures inetd

Linux/390 Specifics
An ASCII implementation
Adds a layer of abstraction to I/O
Channel based v IRQ based
Support for ECKD using SSCH
Support for VM minidisks (ECKD, CKD,
FBA, VDISK)

Linux/390 Specifics
Runs natively, in LPAR, or under VM/ESA
Uses relative instructions: G2, P/390,
R/390 or better
Will use hardware IEEE FP or will emulate
Network drivers for CTCA/ESCON, OSA-
2, and IUCV (VM only)
3215 emulation for virtual console
Hardware console driver (HMC)

Linux/390 Specifics
GNU tools ported
C/C++ compiler (gcc-2.95.1)
Assembler and linker (binutils-2.9.1)
Packages “ported”:
Regina; THE; UFT; X11; OpenLDAP; IMAP;
Sendmail; Bind; RPM; Samba 2.0.6; Apache;
Perl

Linux in the Business
World
Issues and observations

Linux’s place in the market
The business world is interested in:
Efficiency and effectiveness
Networked economy
Network-based businesses

The world is heterogeneous
90% of Fortune 1000 companies use 3 or more
Operating Systems
The demands of e-business
Integrates with existing investments
Supports any client
Applications built/deployed independent of client
24 x 7

Importance of the application model
Server-centric and based on standards that
span multiple platforms
Leverage core business systems and scale to
meet unpredictable demands
Quick to deploy, easy to use and manage

ISVs which have made Linux
announcements:
BEA; Novell; SAP; Informix; Oracle, IBM; HP;
CA; ApplixWare; Star; Corel; Cygnus;
MetroWerks; ObjectShare; Inprise
Media spotlight:
CNN; PCWorld; PCWeek; InternetWeek

Early commercial users
Cendant Corporation - 4000 hotels
Burlington Coat Factory - back office functions
Northwest Airlines - 23 flight simulators
Intel announcement January 5 2000
New web appliances to run Linux
At the insistence of customers (e.g. NEC)

Impacts:
Applications:
Webservers (65%)
WebInfrastructure (mail, DNS) (15%)
File/Print (15%)
DB & DB Applications (2%)
Observations
Linux/Apache share of Web serving high
Autonomous departments
Many SMB and small ISP
CIOs discovering they have Linux running somewhere
Strong mindshare among developers

Linux’s appeal
Embraces new generation of web-based apps
Player in the heterogeneous e-business world
Provides flexibility and choice of environment
Open Source focuses on open standards

Challenges for growth
Products/Technologies/Offerings
Support services
ISV applications
Service providers
Trends
Movement to mainstream
Standards
Ease of use

IBM’s focus on Linux
Services Support offering; Curriculum
Software Porting all key products to Linux
Hardware Intel; RS/6000; S/390
Alliances Partner with Caldera; Redhat;
SuSe
Open Source Support standards & contribute to
bodies

IBM Software Announcements
DB2 Universal Database
Transarc AFS (distributed file system)
On Demand Server
Lotus Domino R5
WebSphere
Tivoli

Summary
Linux is viable in many key application areas
Linux has moved from small technical
projects to significant deployment
IBM claims to be fully supportive of Linux
Part of their heterogeneous strategy
Open source supporter
Hardware, software, and service offerings

Linux
Available Commercial Software

Website Development
ASWedit, HTML
editor
Empress DataWEB
EZ-EDIT
LinkScan
TalentSoft Web+
(WebPlus)
VirtuFlex 1.1
Visual prolog
Web Crossing
ThreadTrack
WebTailor from
Webthreads.

Databases
c-tree Plus
Empress
Essentia
FairCom Server
INFORMIX-SE
Just Logic/SQL
KE Texpress
Qddb
Raima Database
Manager++
Empress Embedded
RDBMS
SOLID Server
Velocis Database
Server
Yard SQL

Data Visualization and CAD
IDL (Interactive Data Language)
Megahedron
Tecplot 7.0
VariCAD
VARKON
XVScan

Development Tools
ACUCOBOL-GT
Amzi! Prolog & Logic
Server
Basmark QuickBASIC
Critical Mass CM3
Dynace
Absoft Fortran 77
Finesse
ISE Eiffel
EiffelBench
C-Forge IDE
IdeaFix
j-tree
KAI C++
Khoros Pro 2.1

Development Tools
MetaCard
ObjectManual Rel 3.0
Critical Mass Reactor
Resource Standard
Metrics
r-tree
sdoc (Source
Documenter)
SEDIT, S/REXX
SNiFF+
ST/X (Smalltalk/X)
tdb (Tcl Debugger)
tprof (Tcl Profiler)
View Designer/X
(VDX)
XBasic
XMove 4.0 for Linux

Emulation Tools
Emulus
Executor 2
Wabi 2.2 for OpenLinux

Financial Software
BB Stock Pro and BB Stock Tool
TimeClock

Libraries
FontScope
INTERACTER
Matrix<LIB> - C++ Math Matrix Library
PKWARE Data Compression Library for
Linux
readyBase
SIMLIB IG

Mathematics
Maple V Release 4 - The Power Edition
MATCOM and MATCOM MATH LIBRARY
Mathematica 3.0
MATLAB and Simulink

Multimedia
Peter Lipa and his Journeys
Lucka Vondrackova and her Journeys
MpegTV Player 1.0
Peter Nagy and his Journeys
Xaudio

Network Servers
Critical Angle X.500 Enabler
DNEWS News Server
Aventail Internet Policy Manager
Aventail VPN
WANPIPE
Zeus Web Server

Office Tools
Corel WordPerfect 8
The American Heritage
Dictionary Deluxe
Applixware Office Suite
D.M.S. Document
Management System
HotWire EasyFAX
NExS, the Network
Extensible
Spreadsheet
Axene Office
Projector and
Projector/Net
The Virtual Office
System
Axene XAllWrite
Axene Xclamation
Axene XQuad

Text Processing
Edith Pro for X11
TeraSpell 97 for Emacs

System Administration
Host Factory
PerfectBACKUP+
Venus

X Windows Related
Accelerated-X
Display Server
BXwidgets
BXwidgets/DB
Laptop, Accelerated-
X Display Server
MaXimum cde
Developer's Edition
v1.0
Multi-headed,
Accelerated-X Display
Server
OpenGL, Accelerated-
X Display Server
OSF-Certified Motif

Other Software
ABACUS 4
BBBS
Clustor
FootPrints
Aladdin Ghostscript
Magician
journyx WebTime
LanSafe
LjetMgr
Synchronize/CyberSc
heduler

UNIX Systems Administrator Resources
http://www.ugu.com/
Linux/390 Observations and Notes
http://penguinvm.princeton.edu
Introduction to Linux
Introduction to UNIX
Linux/390 Installation
Linux Administration Made Easy
http://www.linuxninja.com/linux-admin/book1.html
Conceptual software architecture of the Linux kernel

http://www.linux.org
http://www.tux.org
http://www.li.org

Introduction to Unix

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