Software, Shareware and Opensource CSCU9B2

Transcription

1 Software, Shareware and Opensource CSCU9B2 1

2 Contents Commercial software vs Freeware vs Open Source software Licences GNU GPL Open source Common software examples Sources, Safety and Risks 2

3 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) Sometimes free version has advertising in it 3

4 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 4

5 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 Though this would need programing expertise 5

6 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 So it is free of charge, but not open source 6

7 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 E.g. audio or video recordings 7

8 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 May also be an annual licence 8

9 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 9

10 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 10

11 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 See 11

12 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 See 12

13 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 licensed 13

14 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 redistributed under stricter terms 14

15 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 But training, bespoke development, etc. not free 15

16 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 16

17 Some Good, Free Software Linux (Operating System) Open Office (Office-like tools Firefox and Thunderbird (Browsers) GIMP (Graphics creation, photo editing) PSPP (Statistics) LaTeX (Scientific/engineering word processing) 17

18 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. There are many distributions of Linux 18

19 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 community of users and programmers 19

20 Common Distros 20

21 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 Install the Linux Distro of your choice 21

22 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 22

23 Mozilla Non-profit organisation dedicated to keeping the power of the Web in people s hands See Free software including Firefox browser Thunderbird client Thimble HTML editor 23

24 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 computers (Mac, Linux, Windows ) 24

25 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)) PSPP has a Free software license 25

26 LaTeX Z 1 exp( x 2 )dx 0 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) 26

27 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 or a chat room) without checking it out first Read reviews, use a reputable download site 27

28 Reputable Download Sites Source Forge - sourceforge.net GNU - Tucows And review sites Cnet technology reviews 28