Lesson Objectives Aims You should be able to: Define the terms open source and closed source (proprietary) Be able to discuss the advantages and disadvantages of each

Software Software is: A list of instructions Called “source code” Written in a certain language: VB C C++ JAVA Arnold C etc

Source Source code is the raw program code for a piece of software ALL software, regardless of whether it is open or closed is created from source code

Intellectual Property You will know, when your coursework is done, that writing software is NOT easy. It is a valuable and highly paid skill So most people want to get paid for it, or profit from their hard work by selling their software

Open and closed source The code making up a piece of software is called the “Source Code” Having the source code is incredibly valuable because it shows: HOW a piece of software works Techniques that have been used Which means you could copy it, use someone else’s hard work as the basis for your own or otherwise profit from their work. You naughty person.

This is why most people choose NOT to let people see their code. Open and Closed This is why most people choose NOT to let people see their code. Closed Source means: Software that is proprietary. Software must be purchased or licensed in order to be used and the source code is NOT available and must NOT be altered or used elsewhere.

Open Source Some people believe software should be free and opening it up allows progress to be made, people to learn and avoids discrimination. Open Source is: Software which is released with free, open access to all source code. This code can be freely edited, modified or examined. Any changes made MUST be published.

Closed + and - Advantages Disadvantages Protects intellectual property Can be sold for profit or to recoup development costs All or part of the code may be licensed – if other people want to use it they pay Is a “known quantity” making tracking down bugs/issues easier Potentially (maybe) more secure – harder to work out how it works in order to find weaknesses Fixed functionality (cannot be modified by users) Problems must be fixed by only the manufacturer (delays?) Limited life span (will have end of support date) Increased development costs – programmers must be paid!

Open + and - Advantages Disadvantages Anyone can freely view, edit and modify code Can save a LOT of money in development costs Not paying programmers Basing your code on an existing base is worth a fortune (android, IOS, firefox all did this) Anyone can contribute bug fixes – potential for quicker fixes Anyone can add new features – potential for more rapid development Anyone can add new features – potential to customise software for a purpose All changes made to code must be published You cannot profit from your intellectual property As a programmer you are generally not paid to develop Potential for bugs/issues to not be fixed when found

Examples Find 10 examples of open source and 10 examples of closed source programs What advantages and disadvantages can you see in one of each? What do you think about the quality of each product?