After hacker released to the public details about Firefox URI flaw Mozilla released new version of Firefox – with following security issues fixed:

  1. Unescaped URIs passed to external programs
  2. Privilege escalation through chrome-loaded about:blank windows

First critical and second with moderate impact. Both connected with how Mozilla handle URI protocol.

Time to update again.

Release notes

Microsoft made public Microsoft office 2007 compatibility pack.

This free software will allow users of Microsoft Office 2003, Microsoft Office 2000, and Microsoft Office XP to open, edit, and save files in new Open XML format introduced in 2007 version of Microsoft Office.

Download it now (~27 MB) – requires Live ID

RedHat announced beta release of RHEL 5.1

This release improves/fixes:

  • Virtualization
  • Laptop/Desktop
  • Storage
  • Network
  • Windows compatibility
  • Security
  • …..

For more information see the announcement.

What is that?

Oracle XE – “Oracle Database 10g Express Edition (Oracle Database XE) is an entry-level, small-footprint database based on the Oracle Database 10g Release 2 code base that’s free to develop, deploy, and distribute; fast to download; and simple to administer….

RHEL – is Linux for enterprise environment.

CentOS“is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor.” Aiming for binary compatibility with RHEL.

After first month of releasing CentOS 5.0 one of the questions was will Oracle and RHEL continue to work together and certify their products after release of Oracle Unbreakable Linux -based on RHEL.
Recently Redhat added Oracle Database 10gR2 to their software catalog, but in the meantime Oracle released Oracle Database 11g.

Enough theory let’s start.

First you need to download Oracle XE. I prefer(and recommend) using universal edition.

Then it becomes much simpler.

Just issue(from terminal):

rpm -ivh <path to oracle rpm>

In case of missing packages see my previous post for a way to install them.

After successful installation the installer instruct you to run:
/etc/init.d/oracle-xe configure

for initial configuration. Read carefully the questions and remember system password.

Then you are ready to use XE.

Just start the browser and type:


If you are not familiar with Oracle there are step by step instructions here and here, and official documentation here.


If you cannot access web server after successful installation check your host name it seems that oracle xe do not likes FQDN hostname. In case that you do not have DNS server enter your FQDN in local hosts file.

Credits for the tip goes to Emerson.

Often when installing 3-d party software in RHEL/CentOS or other yum capable Linux OS there is a message of missing libraries or packages.

How to fix it?

Here is the trick.

You can use yum package manager to search for missing pieces.

yum whatprovides <package name/library>

This command will search all configured repositories for package that provides it.
Another option is to search Internet.

TIP: For better stability install only packages in official repositories. OR ones that clearly specify that they work on your OS/version.

Sometimes in troubleshooting process is necessary to turn of firewall for a short period of time.

In Linux based OS usually IPtables is used as firewall. It runs as service and could be stopped, started or restarted. In addition the status could be checked.

Here is how to do it:

Command line

When in terminal type:

Usage: /etc/init.d/iptables {start|stop|restart|condrestart|status|panic|save}

Gives you hints how to use it.

Note that to execute any of actions you need administrative privileges – either login as root, “su -” or setup sudo.

another tool that is doing the same is

service iptables <command>

If you like GUI but use command prompt you can use:


And you will have simple interface of configuring security – firewall and selinux


GUI based

From GUI you can use the same tool just by removing -tui or go to System–>Administration –> Security level and firewall.

Another GUI frienly way is System–>Administration –> Services where you can do the same actions as from terminal.

TIP: Do not leave your system unprotected on Internet. Use cheap SOHO firewall in front of the system until IPtables is set up.

TIP: If you are newbie in firewall configuration use some third party tools as firestarter to guide you in your setup.

NOTE: Above steps are for RHEL (CentOS) compatible systems.

Everybody know about OLPC (one laptop per child) – it is really popular project offering laptop like device for the children of developing countries for about $100.

Several other companies build concurrent projects:

  • Intel – Classmate PC
  • Asus – Eee PC 701 ~ $ 200

Now there is new player on the market Meddison Celebrity offering a Linux laptop for $150 + shipping and taxes.

From company news it seems that it is manufactured in Brazil.

ATTENTION: I’m not affiliate with the company and cannot guarantee anything. There is proverbe: “It’s too good to be true”. Be careful since there is no phone number on their contact page and delivery time is very extended 4-6 weeks + they cannot guarantee that the price will not change. If this is a scam we will know maybe in 3-6 months when first laptops are delivered (or not).

Manual White balance

This feature is present in most high end or “semiprofessional” cameras.

What it does?

Actually you can see it by yourself. Just take a white page and look at it in different lighting. When it is under sunlight it will appear white; Under low light it will appear gray; Under fluorescent lighting – purple … etc.

When digital camera is taking pictures all colors will be shifted and it will be really hard to obtain right colors. Manual white balance comes in help – when you use it point to something that you need to be white and camera will do the corrections for you.

In most of the cameras you have some preset values, but in real live this may not be enough.

Beginner photographs can ignore this feature.

Battery run time

One of important characteristics is how much time camera works on given set of batteries? Does it accept rechargeable batteries or already incorporates an integrated accumulator?

In later case you will need some additional information as:

  • can you charge it in car or you will need to buy optional car charger? – If no you may need to consider buying DC to AC adapter.
  • How much take for the accumulator to charge?
  • What is the life of integrated accumulators? – usually measured in discharge/charge times

Tip: If you need to increase run time consider turning off LCD display. Of course you will need an optical viewer to see what you photograph. Unfortunately most of low cost cameras either do not have one or it “lies” – does not show correct picture area.

Attention: For some of the cameras out on the market the specifications show the time with optional high capacity accumulator and LCD turned off – read the fine-print.


One of important features is what type of storage is used into camera? What is maximum capacity? The recording speed?

Currently several technologies are used in digital cameras:

  • CF – compact flash
  • Micro-drive – miniature hard drive in CF format
  • SD/MMC – secure digital/multimedia card
  • MS – memory stick
  • SM – smart media
  • xD – picture card

They vary in sizes, speed and capacity and are often incompatible. So if your camera uses one you cannot put another format. Some of professional grade cameras are equipped with multiple slots supporting more than one type of card.

After determining the type you can shop for card prices and capacity. Verify camera documentation for maximum supported capacity.

Attention: Some cameras have small amount of integrated memory often impossible to expand.

Every camera has internal memory with capacity enough to store one picture and after you toke the picture the camera cannot take another one until the previous one is stored in storage media. So you need to verify the time need and how many pictures your camera can take before internal memory is filled.

To be continued

Now more about “other” specifications for a Digital Camera.

Angle of view

When photographing a group of people sometimes you need to take them closer together or step back to put all of them in a photo. This is called angle of view it depends on the ratio between the focal length and the film size.

As 35 mm cameras were professional standard, lenses are often described in terms of their “35 mm equivalent” fields of view. This is the difference between a normal lens (e.g. 50 mm), wide-angle lens (e.g. 24 mm), and telephoto lens (e.g. 500 mm). And is particularly common for digital cameras.

Mean values are 30-90mm for 3x zoom cameras.


The noise in the picture is one of most important parameters, but usually the one than is often omitted in characteristics of the camera.

Probably you’ve already seen that on some solid color areas you have dots or lines with different color just like when watching bad videotape on old VCR. This is called “noise”.

Theoretically if camera matrix is bigger there is less noise, but the size is not the only factor, the others like technology, thermal processes even electricity consumption are in play. So the best way of seeing the quality is to make test pictures. As a guide you can use camera sensitivity – usually measured in ISO. Camera with 50 ISO will be not so good as one with 800 ISO. In addition some professional cameras have noise reduction system.


The optic is one of the most important components for a camera. Low quality optic is usually seen when you take pictures with contrasting areas at the edge you could see colorful areas.

The only way to verify is to take test pictures.

Autofocus precision and speed

The precision and speed of autofocus differ from old 35mm cameras. On new digital cameras autofocus could take a second which could be crucial if you are going to take a picture of moving object, but is OK when taking static pictures. In addition autofocus could work properly when you have good lighting(such as taking picture outside), but poorly in low light (like taking picture at home).

Some cameras have low light indication and that is very useful, because in those conditions shutter is in 1/30 s and you need to keep camera steady – not a problem when light is good and shutter is 1/100 s.

to be continued…

How to create coloring page for your kids from photos from your archive.

This howto uses GIMP because it is freely available and do not requires that you buy more software.

For similar guide using photoshop see here.

Note: The picture for this example is taken from here.

What you will need:

  • GIMP – can be downloaded for different paltforms for free.
  • Initial image:

    Pictute for illustrate coloring page from photo

  • Some creativity
  • Printer
  • Pencils

First install GIMP.

Then open the image

Image in GIMP

If needed adjust/crop the image.

Go to Filters–>Artistic–>Photocopy and change the paramethers until you are satisfied.

The result will look like this:


Next step will be to print the image on paper.

Finally use the creativity and pencils to color it.

Have fun….

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