Software, Shareware and
Opensource
Contents
• Commercial software vs Freeware vs Open Source software
• Licences – GNU GPL • Open source
• Common software examples • Sources, Safety and Risks
Pay, Try, Donate, Get Free
• Software can be bought (e.g. Microsoft Office, Logic pro, …)
– Apps or applications
• Shareware – Free to download but limited in some way, either by time or functionality. Buy a license to get full functionality
– Often not able to save files, or watermarks saved files, or…
• Freeware – Obtained at no charge (or optional donation)
Open Source, aka free software,
software libre
• Open Source (or Free software or
Software Libre) is free in a different sense – that of Freedom
• Open Source (not freeware) gives the user the freedom to use, share and modify the program
• The ability to modify requires the source code to be available
• You can charge people for software libre, or give it away, or ask for donations
No Free Shareware
• You cannot release software libre as shareware – that is, with functionality disabled
• Part of the freedom of freeware is that the user has full access to its abilities
• Any disabled features could simply be enabled by editing the source
Commercial Freeware
• Some commercial organisations make software available without charge
– Windows Defender – Adobe Reader
– Google apps
• But it is rare that the source code for these
programs is made available, e.g. Adobe wouldn’t let you change and distribute your own version of Reader
Licenses
• The author of software automatically has copyright of the software
• A software license is a method for allowing others some (or all) rights to use, copy,
distribute or change the software
• This is similar in concept to licenses for other media
Proprietary Licenses
• Proprietary End User License Agreements (EULA) are usually used for commercial software and grant the user permission to use the software
– Long piece of text that you have to click to agree that you’ve read…
• Ownership of the copy of the software actually stays with the company
• Generally states how many concurrent users are allowed, prohibits reverse engineering
and limits liability
Free Licenses
• Free licenses are designed to allow users
greater rights to use, modify and distribute free software
• Some are more strict than others about the terms under which modified versions can be redistributed
• Permissive licenses allow redistribution under different license terms
• Copyleft licenses insist that redistributed code offers the same rights as the license that the original code came with
Copyleft
• Software distributed under a copyleft
license has rights associated with it that must be passed on with the software
• Generally distributed with open source
• Requires that source code for software is made available
• Prohibits restrictions being
added to a modified program’s licence
GNU Project
• Goal to develop “a sufficient body of free
software [...] to get along without any software that is not free.”
• First project was GNU operating system (GNU means GNU’s not Unix)
• Others include compilers, system utilities, games, media manipulation (e.g. GIMP), and many more
GNU GPL
• The General Public License (published by GNU)
• Provides the following user freedoms
– to use the software for any purpose
– to modify the software to suit your needs
– to share the software including any changes you make
• If you share the software, you must share the license
All or Nothing
• Much of what GNU produce (under GPL) and many other GPL licensed software come in the form of a library
• People use these libraries to build new software and then distribute or sell it
• If your software uses a GPL library, then your WHOLE product must be GPL
Using the License
• If you want to release code under GPL, you just download a copy of the license and include it with your code
• If you wrote the code, you still own the
copyright – that isn’t made public domain • You can also release the same software
under a different license – say one which requires payment if the code is
Open Source
• Aka Free Software, Software Libre • Same principles, but different name • Considered less confusing and more
business friendly
• Many companies make a profit from open source software
• The software itself is generally free
Too Much Source
• Some users are happy to download source
code, get all the right libraries, compile the code and run it
– Can be a bit daunting!
• Others would prefer to just download the executable and run it
• Some projects make this easier than others • Some give the impression of being ‘members
only’
• Most software worth having is available as an executable or with an installer
Some Good, Free Software
• Linux (Operating System) • Open Office (Office-like tools
• Firefox and Thunderbird (Browsers)
• GIMP (Graphics creation, photo editing)
• PSPP (Statistics)
Linux
• Linux is a Free computer operating system • Common alternative to Windows
• Desk top versions for PCs • Server versions for servers
• Manages files, devices, hardware, resources, etc.
Linux Distros
• So called ‘Distros’ are versions of Linux that are packaged in different ways
– Different user interface
– Different default configuration
– Different software packages shipped as standard
• Developed and maintained by a
Avoiding Windows
• You can buy a Windows PC or a Mac, and replace the OS with Linux
• You can also use your existing Windows PC and run Linux from a memory stick
• You can also buy a computer without any operating system installed
– This saves you the money of buying Windows
• Can’t easily buy a Mac with no OS: different integration model from Windows
Open Office
• Free alternative to MS office
• Can read MS office documents (mostly)
– Writer (like Word) – Calc (like Excel)
– Impress (like Powerpoint) – Datanase (like Access) – Draw – Vector graphics – Math – Equation writer
Mozilla
• Non-profit organisation ‘dedicated to
keeping the power of the Web in people’s hands’
– See https://mozilla.org.uk
• Free software including
– Firefox browser
– Thunderbird email client – Thimble HTML editor
GIMP
• GNU Image Manipulation Program • Free alternative to Photoshop
• They seem to frown on making a Windows version, but there is a windows installer
available
• Source code is available – Free license • Means you can build it for many different
PSPP
• An alternative to (you guessed it) SPSS • Statistical analysis
• Another GNU product
• SPSS licencing is considered unethical (or at least quite harsh (time limitations, for
example))
LaTeX
• For the more mathematically inclined amongst you, LaTeX is a typesetting program
• Produces documents, e.g. PDF with very nice typesetting
• Used a lot in academia, specifically in science and engineering
• Very satisfying, once you get the hang of it
– Very nicely formatted equations etc.
• Specify your document in a mark-up language, then compile
• LaTeX compiler is free under the LateX Project Public License (LPPL)
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Risks and Safety
• Most free software is distributed as downloads via the internet
• Most of it is safe and reliable • Some of it contains malware
• Never download something a stranger has recommended (say in email or a chat
room) without checking it out first
Reputable Download Sites
• Source Forge - sourceforge.net • GNU - www.gnu.org/software • Tucows – www.tucows.com • And review sites
