1. Computer Software Chapter 4 Copyright © 2010 by the McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin

2. 4-2 Learning Objectives Describe several important trends occurring in computer software Give examples of several major types of application and system software Explain the purpose of several popular software packages for end user productivity and collaborative computing

3. 4-3 Learning Objectives Define and describe the functions of an operating system Describe the main uses of computer programming software, tools, and languages Describe the issues associated with open source software

4. 4-4 Types of Application & System Software

5. 4-5 Application Software Custom Commercial Off-the-Shelf (COTS) General Purpose Open-Source Application Software

6. 4-6 Business Application Software Thousands of these packages support specific end-user applications Customer Relationship Management Enterprise Resource Planning Supply Chain Management Function-Specific Application Software Web-enabled electronic commerce

7. 4-7 Software Suites, Integrated Packages Most widely used productivity packages are bundled as software suites Advantages 1. Cost less than buying individual packages 2. All have similar GUI 3. Programs work well together Disadvantages 1. All features not used 2. Takes a lot of disk space (bloatware)

8. 4-8 Components of Top Software Suites

9. 4-9 Integrated Packages Integrated packages combine the functions of several programs into one package E.g., Microsoft Works, AppleWork Advantages 1. Many functions for lower price 2. Uses less disk space 3. Frequently pre- installed on PCs Disadvantages 1. Limited functionality

10. 4-10 Web Browsers Software that supports navigation through point-and-click, hyper-linked Web resources Becoming the universal platform from which end users launch… Information searches E-mail Multimedia file transfer Discussion groups Other Internet-based applications

11. 4-11 Search Engines Google, Ask Jeeves, Look Smart, Lycos, Overture, Yahoo! Browsers are used to gain access to Internet search engines Using search engines to find information has become an indispensable part of Internet, intranet, and extranet applications

12. 4-12 E-mail, Instant Messaging, Weblogs E-mail –Sending and receiving messages and attachments via the Internet, intranet, or extranet Instant messaging (IM) –Receive electronic messages instantly Weblog or blog –A personal website in dated log format –Updated with new information about a subject or range of subjects

13. 4-13 Word Processing/Desktop Publishing Word Processing –Create, edit, revise, and print documents –E.g., Microsoft Word, Lotus WordPro, Corel WordPerfect Desktop Publishing –Produce printed materials that look professionally published –E.g., Adobe PageMaker, Microsoft Publisher, QuarkXPress

14. 4-14 Electronic Spreadsheets Used by virtually every business for analysis, planning, modeling Worksheet of rows and columns Can be stored on local computers or a network Requires designing format and developing the relationships (formulas) Most help you develop charts and graph displays of spreadsheet results Supports what-if questions

15. 4-15 Presentation Graphics Microsoft PowerPoint, Lotus Freelance, Corel Presentations Are used to create multimedia presentations of graphics, photos, animation, video Top packages can tailor files for transfer in HTML format to websites Convert numeric data into graphics Common presentation graphics packages…

16. 4-16 Personal Information Managers Manages schedules, appointments, tasks Most have ability to access the Web and e-mail Stores information about clients Some support team collaboration by sharing information with other PIM users e.g., Lotus Organizer, Microsoft Outlook Software for end user productivity and collaboration

17. 4-17 Groupware Software that helps workgroups collaborate on group assignments –E-mail, discussion groups, databases, audio, and video conferencing –E.g., Lotus Notes, Novell GroupWise, Microsoft Exchange –Windows SharePoint Services and WebSphere both allow teams to create websites for information sharing and document collaboration

18. 4-18 Software Alternatives Outsource software development and maintenance Application service providers (ASPs) –Companies that own, operate, and maintain application software and computer system resources –Use the application for a fee over the Internet –Pay-as-you-go –Use expected to accelerate

19. 4-19 Cloud Computing Software and virtualized hardware resources are provided as a service over the Internet –No technology knowledge, expertise, or control needed –Often confused with grid computing –Pay-for-use avoids capital expenditures –Sharing “perishable and intangible” computer power improves utilization rates –Capacity can be scaled upward almost instantly –Immediate access to broad range of applications –Contracts can generally be terminated at any time

20. 4-20 Software Licensing Trade secrets COTS and ASP software is licensed, which involves… You buy a license to use the software Licensed to protect vendor’s property rights You don’t buy software… Traditional contract law, including Uniform Commercial Code (UCC) Copyright and trademark Intellectual property rights

21. 4-21 Case 2: Power Distribution & Law Enforcement XML is becoming increasingly popular as an open standard for sharing data across organizations A power consortium is implementing an XML-based settlements system that drives costs out of power distribution In Ohio, almost 1,000 police departments now have access to digital records kept by neighboring law enforcement agencies The Ohio Law Enforcement Gateway Search Engine is an Internet- based tool that can securely comb through numerous crime databases with a single log-in and query

22. 4-22 Case Study Questions What is the business value of XML to the organizations described in the case? –How are they able to achieve such large returns on investment? What are other ways in which XML could be used by organizations to create value and share data? –Look for examples involving for-profit organizations to gain a more complete perspective on the issue What seem to be important elements in the success of projects relying on extensive use of XML across organizations, and why? –Research metadata to inform your answer

23. 4-23 Categories of Group Software System Management Programs System Development Programs Manages hardware, software, network, and data resources of computer systems Operating systems, network management programs, database management systems, system utilities Helps users develop IS programs and procedures, and then prepare them for processing Includes language translators and editors, CASE, and programming tools

24. 4-24 Interface Between End Users & Computer

25. 4-25 Operating Systems Integrated system of programs that… Provides support services as the computer executes application programs Manages the operations of the CPU Controls the input/out, storage resources, and activities of the computer system The operating system must be loaded and activated before other tasks can be accomplished

26. 4-26 Operating System Basic Functions Command-driven Menu-driven Graphical User Interfaces (GUI)

27. 4-27 Popular Operating Systems Windows –GUI, multitasking, networking, multimedia –Microsoft’s operating system –NT, XP, 2003 –Different versions manage servers Standard, enterprise, data center, Web Unix –Multitasking, multi-user, network-managing –Portable - can run on mainframes, midrange, and PCs

28. 4-28 Popular Operating Systems Linux –Low-cost, powerful, reliable, Unix-like operating system –Open-source MAC OS X –Apple operating system for the iMac –GUI –Multitasking –Multimedia

29. 4-29 Open Source Software The basic idea –When programmers can read, redistribute, and modify source code, the software evolves –This can happen at astonishing speed –Produces better software than the traditional commercial (closed) model –The proprietary approach to software development has hidden costs that often outweigh its benefits

30. 4-30 Open Source Software Open source software is not… –Shareware –Public domain software –Freeware –A viewer or reader made freely available without source code OSS… –Is copyrighted & distributed with license terms –Sometimes carries a fee for packaging, distribution, or support

31. 4-31 Open-Source Licensing Characteristics The License –The program must include the source code and allow distribution in source code as well as compiled form –Shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several sources –Must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software

32. 4-32 Open-Source Licensing Characteristics The License (continued) –May restrict source code from being distributed in modified form only if the license allows the distribution of patch files with the source code for the purpose of modifying the program at build time –Must not discriminate against any person or any group of persons –Must not restrict anyone from making use of the program in a specific field of endeavor

33. 4-33 Open-Source Licensing Characteristics The License (continued) –The rights attached to the program must apply to all to whom the program is redistributed, without the need for execution of an additional license –Must not be specific to a product –Must not contaminate other software by placing restrictions on any software distributed along with the licensed software

34. 4-34 Examples of Open Source Software Open Office –Can be used for any purpose: domestic, commercial, educational, or public administration Mac OS X –Based on a form of UNIX –Advanced GUI –Supports multi-tasking and multimedia –Integrated Web browser, e-mail, instant messaging, search engine, digital media player, and more –Includes software development tools

35. 4-35 Application Virtualization An umbrella term for software technologies that improve portability, manageability, and compatibility of applications –Works by insulating applications from the underlying operating system Benefits –No need for multiple platforms for multiple applications –Energy savings from not having servers running at low capacity

36. 4-36 Other System Management Programs

37. 4-37 Other System Software Utilities –Miscellaneous housekeeping functions –Example: Norton utilities includes data backup, virus protection, data compression, etc. Performance Monitors –Programs that monitor and adjust computer system to keep them running efficiently Security Monitors –Monitor and control use of computer systems to prevent unauthorized use of resources

38. 4-38 Application Servers Provide an interface between an operating system and the application programs of users Middleware –Helps diverse software applications exchange data and work together more efficiently

39. 4-39 Programming Languages

40. 4-40 Machine Languages First Generation Languages The most basic of programming languages Strings of binary codes unique to each computer Requires specific knowledge of the internal operations of the CPU being used Must specify the storage location for every instruction and item of data used Difficult to work with, and error prone

41. 4-41 Assembler Languages Second Generation Languages Developed to reduce difficulties in writing machine language programs Uses assemblers to convert the programs into machine instructions Symbols used to represent operation codes and storage locations Alphabetic abbreviations, call mnemonics, and other symbols represent operation codes, storage locations, and data elements

42. 4-42 High-Level Languages Third Generation Languages Uses brief statements or arithmetic expressions Statements translated into machine language by compilers or interpreters Less efficient than assembler language and requires greater translation time Machine dependent Examples: BASIC, COBOL, FORTRAN

43. 4-43 Fourth-Generation Languages Variety of programming languages that are nonprocedural and conversational Programmers specify the result wanted; the computer determines the sequence of instructions that accomplish the result Simplifies the programming process Natural language; very close to English Sometimes called fifth-generation (5GLs)

44. 4-44 Object-Oriented Languages

45. 4-45 Object-Oriented Languages Easier to use and more efficient for graphics- oriented user interfaces Most widely used software development languages Reusable: can use an object from one application in another application Examples: Visual Basic, C++, Java Most object-oriented languages provide a GUI that supports visual programming

46. 4-46 Web Languages HTML A page description language that creates hypertext documents for the Web XML Describes Web page content by applying identifying tags or contextual labels to the data Java Object-oriented programming language that is simple, secure, and platform independent Java applets can be executed on any computer

47. 4-47 J2EE versus.Net

48. 4-48 How Web Services Work

49. 4-49 Language Translator Programs Translate instructions written in programming languages into machine language Assembler Translates assembler language statement Compiler Translates high- level language statements Interpreter A compiler that translates and executes each statement in a program, one at a time

50. 4-50 Programming Tools Help programmers identify and minimize errors while they are programming –Graphical programming interfaces –Programming editors –Debuggers CASE Tools –A combination of many programming tools into a single application with a common interface –Used in different stages of the systems development process