2001.11_Brave Gnu World-the Monthly Gnu Column.pdf

BRAVE GNU WORLD

COMMUNITY

BRAVE GNU

WORLD

GEORG CF GREVE

Welcome to another issue of the

Brave GNU World. Since all work

and no play makes Jack a dull boy,

I’ll introduce a Free Software game

this month. But before I do I’d like

to say a few words about Free

games in general.

Free Games?

portal that is exclusively dedicated to Free games

would be quite useful. Enough introduction for

now, let’s get started.

Georg

Because of their small servicing needs and

fast-paced market, Free games are a rather

problematic area, even if some companies are now

port games to GNU/Linux, these games usually

remain proprietary.

Of course it is true that games are usually not

mission-critical and not the most important part of

Free Software. But this does not make them

insignificant. Games are often the first contact

people have with their computers and play a

significant role in “befriending” themselves with

their computer. And quite often games are the

“killer feature” that makes them install a non-free

operating system on their machines.

Another issue is that the gaming industry seems

to be replacing innovative ideas with more and

more effects. This may be a quite subjective

impression and not hold up to scrutiny, but it very

often seems that the first games were significantly

more witty.

In this area the interaction of a community might

open new perspectives for captivating, nonlinear

plots. It appears this potential is not yet being used.

Very often lacking a user base is a problem for

new areas, so I’d like to introduce Free games in the

Brave GNU World more often. If you are having fun

with a Free game or are working on one yourself,

please get in touch. Also information about a

Freeciv

Freeciv is a Free implementation of the well-known

game Civilization by Microprose under the GNU

General Public License.

For those not having experience with the game

Good graphics in Freeciv, a free variant of Civilization.

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The monthly GNU Column

COMMUNITY

BRAVE GNU WORLD

mentioned above I’d like to say that the game is

about becoming the ruler of a civilization and taking

care that your people grow and prosper. This

involves finding resources, building cities, furthering

science and keeping competitors at bay. A major

advantage of the game is its nonlinearity and the

continuous evolution, which makes it so hard for

many to find an end when playing this game.

Freeciv is already quite sophisticated and a player

can choose between 47 units and 61 nations that

can be played in prepared maps and scenarios. The

game is also internationalized, so it speaks to the

player in his or her mother tongue and has an in-

game help.

One of the extraordinary thing about Freeciv is

the very active and lively community that has

evolved around it and communicates through the

#freeciv ircnet-channel. One reason for this is surely

that Freeciv supports up to 30 players that can

either be played by an “artificial intelligence” (ai) or

by a networked human player (LAN or internet).

Also Freeciv runs on all standard Unices as well as

Windows and OS/2, given that the Cygnus Unix-

environment is installed.

Originally, Freeciv was started by Peter Joachim

Unold, Claus Leth Gregersen and Allan Ove

Kjeldbjerg, but by now the administration is done

by Thue Janus Kristensen and Tony Stuckey. Besides

these people, an impressive number of volunteers

have contributed to the versions that routinely

come out in three-month cycles. You can find the

list online at Freeciv.org.

Microsoft-users are currently experiencing the

greatest problems, but these could easily be solved

by installing GNU/Linux. Other problems are caused

by the extreme addictiveness and time-consumption

of Freeciv, so if you’re currently working on an

important project, you might want to postpone

trying out Freeciv until the project has been

finished.

Stefan Kamphausen, author of the Brave

GNU World logo, has tracked down the

following project.

everything is based on XML, even the Makefiles.

The HTML-pages created by XWeb are entirely

independent from XWeb, so they can be transferred

to a web server by FTP, for instance.

Other than some XSL-processors, XWeb also

allows the automatic generation of buttons,

banners and such through an internal renderer or

the external generation of “Scalable Vector

Graphics” (SVG) by Batik.

These features combined with the flexibility

through use of XSLT stylesheets are the specific

strengths of XWeb.

The project is mostly pushed forward by its

initiator, Peter Becker, who started the project

because he was lacking this functionality in

another project.

XWeb is Free Software, even if the licensing as

“public domain” is not optimal, because it allows

anything to putting it under your own copyright. So

the freedoms are not protected in any way.

Plans for the future are to complete the program

and include support for XSL-FO as well as

generating templates for the most often used

layouts. Later he’d like to add application-specific

frontends (for photo- or MP3-albums, for example)

and maybe even a WYSIWYG tool.

Help is welcome especially in form of authors

for templates and frontends as well as feedback

from users.

General Server Pages

The General Server Pages (GSP) project by

Sebastien Devaux is also related directly to the

internet, although it is more on the dynamical

side. GSP is a preprocessor which allows for

extremely easy creation of applications for

structured output in different programming

languages – which is especially useful for creating

CGI applications.

Writing CGI applications very often means

repeating big amounts of rather trivial code with

XWeb

XWeb allows writing content

and structure of web pages

in XML/XSL in order to

generate HTML pages from

it. This does not only offer a

performance advantage

compared to dynamic pages,

it also allows switching to a

new layout or design with

minimal changes. Especially

the often quite significant

but seldom entertaining work of creating the

navigational structure is done for the user by XWeb.

XWeb is based on Java & XSLT with Saxon as the

XSLT processor. Other than with some projects,

The General Server pages – here with a variation in C

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BRAVE GNU WORLD

COMMUNITY

the goal of creating a certain output. Therefore

GSP allows specifying the output in a mixture of

XML, GSP and the desired programming language

in order to be transformed by GSP into a

compilable source code or script creating the

desired output as HTML, XML, SGML or plain text.

This does not only spare time and nerves, it also

increases the reusability of code. Programming

languages currently supported by GSP are C, C++,

Bash, Ksh, Perl and JavaScript; adding other

languages is pretty simple. GSP can also create

applications containing several pages and link

them with each other.

GSP was written in C++ and published under

the GNU General Public License. It is still a rather

young project as it started in February 2001.

Problems are still the correct handling of MIME

extensions as this requires external libraries, but

this choice should be up to the user. The modules

for the different languages can also be improved

and Sebastien would like to make very sure that

the generated code is safe. Help is welcome.

A PKI does not only allow identification and

authentication, it also allows confidential

information, integrity of data and non-

repudiation in case of problems.

All these things are important to many

companies, but banks, insurances or e-commerce

markets depend on it.

Now these companies have access to a Free

Software solution, which is a big contribution to

Free Software by IdealX.

Originally, the project team tried to get

involved in the OpenCA project. But OpenCA is

only a CA and not a complete PKI, it only allows

for creation of certificates through OpenSSL, but

it does not provide certificate management.

Therefore IDX-PKI was started in April 2000.

The IDX-PKI uses Perl, PHP, C, Shell as well as

some GNU utilities and it is now ready for daily

use although it is still being improved. Planned

are (among other things) a capability for secure

communication between different PKIs, full

OCSP support and another abstraction layer

that will make it possible to choose the

backend (database, LDAP, filesystem).

Also the administration will become

interface-independent.

So there are still some things in the queue, but

according to Benoit Picaud the customers are

very interested in this project and actively support

the speedy and interactive development of the

IDX-PKI-v2. He is even considering this strong

cooperation to be one of the big strengths of the

project - along with the RFC-compliance.

Since this is a project that is also commercially

interesting for many other companies, finding

help should not pose a problem.

IDX-PKI

The IDX-PKI project is the first IETF PKIX

standards-compliant “Public Key Infrastructure”

available as Free Software. It was developed

by the French company IdealX that publishes

and maintains it under the GNU General

Public License.

Since the term PKI is probably not familiar to

many readers, I’d like to give a very terse and

abstract introduction into the idea behind it.

In any “Public Key” implementation, like PGP or

the Free OpenPGP implementation GnuPG, every

user has a keypair. This keypair consists of one

private and one public key. The private key must

never leave the users hands, while the public key

is spread as far as possible.

The private key allows the user to (for instance)

sign Emails and everyone can verify the signature

with the public key. Signing the mail with the

public key is not possible, so the recipient knows

that the mail has been signed by the owner of the

private key.

But anyone can create a key, so there is no

guarantee that the private key really belongs to

the person it claims to belong to.

A solution for this problem is a “Certification

Authority” (CA). This is often provided by so-

called TrustCenters that make sure the identity of

the users has been checked. Providing a

Certification Authority is one of the primary jobs

for a PKI.

The IDX-PKI project allows every company and

organization to set up their own CA-structure.

This makes it possible to put the exact same

amount of trust that you have into the company

into every single employee. The tasks of creating

and revoking keys is done centrally by the PKI.

Enough for this time

That’s it for this month, I hope I was able to drive

your interests and, as usual, I’m asking for

comments, ideas, feedback and project

Info

Send ideas, comments and questions to

Brave GNU World column@brave-gnu-world.org

Home page of the GNU Project http://www.gnu.org/

Home page of Georg’s Brave GNU World http://brave-gnu-world.org

“We run GNU” initiative

http://www.gnu.org/brave-

gnu-world/rungnu/rungnu.en.html

Freeciv home page

http://www.freeciv.org

People involved in Freeciv

http://www.freeciv.org/people.phtml

XWeb home page

http://xweb.sf.net

Saxon home page

http://saxon.sourceforge.net

Batik home page

http://xml.apache.org/batik

General Server Pages (GSP) home page

http://gsp.sourceforge.net

GNU Classpath Extensions home page

http://www.gnu.org/software/classpathx

GNU Classpath home page

http://www.gnu.org/software/classpath

GNU Java home page

http://www.gnu.org/software/java

IDX-PKI home page

http://idx-pki.idealx.org

14 · 2001 LINUX MAGAZINE 93

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