Presentation software

A presentation program is a computer software package used to display information, normally in the form of a slide show. It typically includes three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images and a slide-show system to display the content.

There are many different types of presentations including professional (work-related), education, worship and for general communication. Presentation programs can either supplement or replace the use of older visual aid technology, such as Pamphlets, handouts, chalk boards, flip charts, posters, slides and overhead transparencies. Text, graphics, movies, and other objects are positioned on individual pages or "slides". The "slide" analogy is a reference to the slide projector, a device which has become somewhat obsolete due to the use of presentation software. Slides can be printed, or (more usually) displayed on-screen and navigated through at the command of the presenter. Transitions between slides can be animated in a variety of ways, as can the emergence of elements on a slide itself.

The most commonly known presentation program is Microsoft PowerPoint, although there are alternatives such as OpenOffice.org Impress and Apple's Keynote.

Many presentation programs come with pre-designed images (clip art) and/or have the ability to import graphic images. Custom graphics can also be created in other programs such as Adobe Photoshop or Adobe Illustrator and then imported.

With the growth of digital photography and video, many programs that handle these types of media also include presentation functions for displaying them in a similar "slide show" format. For example, Apple's iPhoto allows groups of digital photos to be displayed in a slide show with options such as selecting transistions, choosing whether or not the show stops at the end or continues to loop, and including music to accompany the photos.

Similar to programming extensions for an operating system or web browser, "add ons" or plugins for presentation programs can be used to enhance their capabilities. For example, it would be useful to export a PowerPoint presentation as a Flash animation or PDF document. This would make delivery through removable media or sharing over the Internet easier. Since PDF files are designed to be shared regardless of platform and most web browsers already have the plugin to view Flash files, these formats would allow presentations to be more widely accessible.

History
Originally these programs were used to generate 35mm slides, to be presented using a slide projector. As these programs became more common in the late 1980s, several companies set up services that would accept the shows on diskette and create slides or print transparencies. In the 1990s dedicated LCD-based screens that could be placed on the projectors started to replace the transparencies, and by the late 1990s they had almost all been replaced by video projectors.