This is Alan Pope with the third screencast in the
Ubuntu Month Of Screencasts.
All the screencasts in this month can be downloaded for free
from our website, which is screencasts.ubuntu.com
Today we are going to look at freedom and software licenses.
This is a massive subject and I am not a great expert on software licenses,
so you will have to bear with me on this.
Freedom can be seen in different ways by different people.
I will give you some examples of how people perceive freedom,
when they are using computers and computer devices.
Here is a diagram that was created a couple of years ago by a friend of mine
and it represents my local network.
Now I have changed my network in the last couple of years
and I would like to update this diagram.
But in order to do that, because the file format is not open
it is a closed format.
I would need to go and buy a copy of the program, Visio
and buy a copy of the operating system it runs on, Windows,
in order to make changes to this file,
because the format is closed.
That is what we call vendor lock-in.
I am locked to using that vendor for that software.
That is one element where my freedom is restricted.
I can not make changes to my own files.
Another example of lack of freedom
is in the video driver for my 3-D card.
I have an NVIDIA card and NVIDIA provide a
binary only, no source code driver.
Which means that when somthing goes wrong with that driver
there is no way for the developers
of Ubuntu or any other developer that I know,
to look at the code, because NVIDIA do not release it.
That makes maintainence and support very difficult.
Another area where people perceive freedom as being restricted is
in the ability to play media they have downloaded or bought,
on the device of their choice.
Not one that is imposed by the vendor.
Another example is downloading media and paying for it
and finding that the vendor has now shutdown the service
or gone out of business.
You are now no longer able to play the media that you paid for.
That is obviously restricting your freedom to play
what you thought you had bought.
The way in which that is usually implemented
is with technological software locks
Which is often called DRM, Digital Rights Management
or as the Free Software Foundation call it
Digital Restrictions Management.
This is software that prevents you being able to do stuff
with the media that you download or buy.
There are three examples, Googlevideo, the BBC iPlayer and iTunes.
Another element of freedom is being able to make changes to
media such as images, video, music and create derivative works.
It may be that it is not allowed.
In addition to which you might want to
copy something, and make duplicate copies for your friends
and that also may not be allowed.
That is usually restricted not through DRM,
but through a restricted End User Licence Agreement.
or just just Licence,
that prevents you being able to make copies
It does not technically prevent you,
but legally prevents you being able
to make copies or derivative forms of media.
Here is an example of a restrictive End User Licence Agreement.
This is the Skype End User Licence Agreement
You can see there section two point three, no modifications.
You are not allowed to make changes to the skype program.
So even if you wanted to improve it, you can not.
Even if you wanted to integrate skype with some other product in some way
you can not because you are not allowed to make changes to the program.
Here is another restrictive End User Licence Agreement.
Windows XP Home Edition licence
You are not allowed to
give that copy of XP on a computer to another person.
and then them give it to somebody else.
You can only do that once.
So if someone gives me a computer running XP
I can not then give that computer to somebody else,
when I have finished with it.
Compare that with permissive free software licenses,
which we use a lot in Ubuntu.
So what is a free software license?
Well this is straight from Wikipedia,
It grants you the rights to modify and redistribute the software,
which might otherwise be restricted by copyright law.
So this means you might be able to make changes, improve,
fix and redistribute programs,
where a restricted license might not let you.
One of the most popular permissive free software licenses is
the GNU General Public Licence, GPL.
GNU was started over twenty years ago by Richard Stallman.
We will look at some links later on,
where you can find out more information about this.
As I said, this is not my area of expertise,
but I will give you an introduction and there is more information
in plenty of of places on the web.
The GNU GPL is what is used by the Linux kernel
and many other free software projects as well,
that make up the Ubuntu distribution.
So Ubuntu has lots of software products
packaged together in a distribution
and they may all have different licenses.
You can find a copy of those licenses on your Ubuntu machine
in this directory, /usr/share/common-licenses.
These are some of the more common licenses.
Funnily enough, with the name of the directory.
GPL, the BSD license and the LGPL.
If you want to know the license a program or a package
is licensed under, you can have a look in this directory.
/usr/share/doc/and then change the little
asterisk for the package name you want to check
and there is a copyright file in there.
For example here is the copyright file for the Linux kernel.
Now you probably can not read this text,
but if you go and open this file you will find
that it says about half way down,
This program is free software, you can redistribute it
and/or modify it under the terms of the
GNU General Public License,
published by the Free Software Foundation, version two.
So therefore the Linux kernel is licensed under the GPL version two.
Another package is Tomboy, which is supplied with Ubuntu
It is a great note taking application.
If we look at the copyright file for that,
it says Tomboy is licensed under the LGPL version two point one.
So what we have here is multiple different packages,
different applications within the distribution.
Some of those applications use different licenses,
but those licenses are permissive enough
that the files can be put together within one distribution
and sold as one entity.
There is a lot more information about this online
and I would highly recommend if you want to know more
you can read those licenses.
They are a bit dry to read on their own, but they are
surprisingly not too legal, full of legalese that is.
Here are a few links that might be useful.
I will put these links on the website, if you go to
screencasts.ubuntu.com and click on this
you will find these links.
The first one is on wikipedia, there is a page about free software.
It describes what free software is and the ethos of
being able to redistribute, modified or unmodified,
without restriction or maybe with restriction,
depending upon the license.
There is also a page on Wikipedia about GNU,
and the history of GNU and the projects that GNU have
and the programs that GNU have under their license.
Then if you go to the GNU homepage there is
a tremendous amount of information about GNU
and also a little bit here at the top about
the naming of GNU and GNU/Linux or GNU+Linux.
Here is a little section, I'll just make a bit bigger,
and here is the four freedoms, that are enshrined in the GNU GPL.
Freedom to run the program,
freedom to study the program,
freedom to redistribute the program and
freedom to improve the program and then
release your improvements.
You will notice access to the source code is a pre-requisite
for being able to study and modify the program.
There is also a great set of pages about the philosophy
of free software and these are worth a read.
Also worth looking at is the Free Software Foundation.
The Free Software Foundation's website is fsf.org
and they promote freedom in computing.
There is also a couple of great pages on Wikipedia about the list of
approved software licenses.
So the Free Software Foundation and Open Source Initiative
ratify whether licenses are "free" or "open".
Here is an example where something is free,
but the PHP license is incompatible with the GPL,
because there are terms in each that conflict with each other.
So it is difficult, you could not create a program that is
part based on a GPL program and
part based on a PHP licensed program,
because the licenses are incompatible.
There is a bit about incompatibilty of licenses within those pages.
So it is worth having a read of some of those pages,
when you have a bit of time.
Many thanks for watching.
All of the screencasts are available on our website,
screencasts.ubuntu.com