29 june 2007: NLUUG Event Enschede

Friday June 29, the NLUUG will organise an event with the theme innovation in IT.

Lectures will be held in Dutch or English. Slides available in the closed member area.


Friday June 29 2007, 13:30 - 17:30


Ondernemershuis Enschede
Hengelosestraat 585
7521 AG Enschede
How to get there: by car

by public transportation: Take the train to Hengelo. Trains leave from Schiphol airport with 30 minutes in between; their end station is Enschede, but it's a little easier to get off in Hengelo. In Hengelo, go to the bus station and take bus 9. Be sure to check the end point of the line, which should be Enschede. You will be charged a 2 zone (3 strips) fair. Ask the driver to signal you when he gets at the Assinkhof bus stop. After getting off the bus, continue in the same direction for about 1 minute, that is, in the direction of Enschede. You will find the location at your right hand.

The location and drinks are provided by Syntens

Entrance fee

FREE (as in free beer).


The slides of the presentations can be found below.


To assure yourself of a place, please register by sending an email to,
including your name and (if applicable) organisation.
You will receive a reminder by email just before the event.

PGP key-signing and CAcert certification

During the break there will be PGP key-signing and CAcert certification.
More information and instructions can be found here (Dutch only).


13:00 - 13:30

Welcome with coffee/tea

13:30 - 14:15

The Linux cowloop device driver
Hendrik-Jan Thomassen (AT Computing BV)


Hendrik-Jan Thomassen The cowloop device driver for Linux systems allows other block-devices to be used in a read-write fashion without writing to that block-device itself. Write operations are intercepted, and diverted to a separate regular file, called the "cowfile". This cowfile can be chosen freely on any writable filesystem (disk, USB stick...). The underlying block device is effectively shielded from actual write accesses.

The cowloop driver exports 16 block-dev names, called the "cow-devices", to the user. An administrative command connects one of these cow-devices to a pair of (1) block device to be shielded, plus (2) cowfile to store the diverted writes. Then the cow-device special file name can be used in a mount-command (rw), which opens access to the file system tree on the underlying block-device without ever writing to it.

After a subsequent unmount, the underlying block device is guaranteed to be unmodified. All "modified" sector-images are stored in the separate cowfile. If the same pair of block device to be shielded plus cowfile is reused later, the file system tree on the underlying device reappears in its "as last modified" form.

Similar to the well known loopback-mounting technique, cowloop also supports the use of a file-system-in-a-file instead of a block device to be shielded.

More info on


Hendrik-Jan Thomassen is the director of AT Computing and AT Consultancy in Nijmegen. Both companies specialise in UNIX/Linux related activities exclusively. Hendrik-Jan has worked with UNIX for over thirty years. He is one of the founding members and a honorary member of the NLUUG.


14:20 - 14:50

OASE and the results
Carlos Silva dos Santos (Syntens)


Carlos Silva dos Santos From 2002 to 1 April 2006, Syntens implemented the OASE (Open Aanbod Software Expertise / Open Supply of Software Expertise) programme with a subsidy from the Ministry of Economic Affairs (1.362 million euro). OASE was launched as a pilot project within the Syntens project structure for the multi-annual programme Nederland Gaat Digitaal (The Netherlands Goes Digital - NGD). NGD focused on technology-following SMEs.
The idea was that by applying OSS, a potentially greater number of generic cores could be made software-specific for a single business or group of businesses, at lower costs than through customised application based on closed source software (CSS). Businesses that previously only followed technological developments could thereby become businesses leading technological developments. Syntens already had contact with more than 80 trade associations via NGD. On account of the multiplier effect, the sector-oriented stimulation of demand-driven OSS was chosen. The results will be presented.


Carlos Silva dos Santos, is innovation advisor for SME's at Syntens and is project manager of the OASE project. His passion is advising in the use of ICT as a stratigic tool for SME's.


14:50 - 15:20

Coffee/tea break
During the break there will be PGP key-signing and CAcert certification.
More information and instructions can be found here (Dutch only).

15:20 - 16:00

Automatic test case generation, execution and evaluation with TorX
Machiel van der Bijl (Axini)


Machiel van der Bijl In this presentation we give an overview of the possibilities of the open source test tool TorX. TorX makes it possible to automatically generate, execute and evaluate test cases based on a specification of the system under test (this also known as model based testing). We end the presentation with a short tool demo.


Machiel van der Bijl is specialized in automatic testing. He is the owner of Axini, a company specialized in testing of complex systems. Before he started Axini he has been working as a software consultant in several areas, for example for banks/insurance companies and embeddes systems manufactureres. Right now he is finalizing his PhD research on model based testing.


16:05 - 16:45

Efficient XML in a database using MonetDB/XQuery Maurice van Keulen (University of Twente)

Abstract Maurice van Keulen With growing volumes of XML data, it is a logical thought to store the XML data in a database. Support for XML in existing relational databases is, however, rather clumsy and inefficient, and special XML databases are limited and immature. This presentation explains a new way of storing XML in an ordinary relational database that enables efficient querying and updating. MonetDB/XQuery is an open source database based on this technique which additionally has some interesting extensions for multimedia applications.


Maurice van Keulen is assistant professor at the University of Twente. His research interests include topics like XML databases, schema and data integration, uncertainty in data, data quality, data heterogeneity, semi-structured data, (multimedia) information retrieval, and DBMS extensibility.


16:50 - 17:30

GPL V2/V3: Business Compatible?
mr. drs. Walter van Holst (Mitopics)


mr. drs. Walter van Holst This presentation focuses on the various business models in IT and how open source licenses, especially the GPL, influence the viability of such business models. Special emphasis will be put on the likely changes that will stem from the next version of the GPL, version 3 and their impact on open source business models.


Walter van Holst is a IT legal consultant with Mitopics, a consulting firm specialising in the relationship between vendors and customers of IT. He has a background in both law and business and before joining Mitopics he was an IT consultant in the telecommunications industry for over four years.

Slides will appear on the Mitopics website

17:30 - 18:30


Last update: June 27 2007

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