In this post we’ve emphasized:

1. Price of software
Subscription or one-time fee, Free as in free beer, or free with ads/watermark?

2. Ownership of presentation media
Are your presentations created and saved offline or do they have to reside on some public cloud server.

3. Portability of presentation format
Are your presentations created in a proprietary closed format and if so, can it be exported to common file formats like PPTX, PDF, etc?

4. Track record of provider
Has the provider been around for a long time and do they have a reputation of treating their customers well?

5. Features
Do the software stand out as being rich on useful features for presentation authors?

6. Supported operating systems
Is the presentation authoring software available on several platforms? If not, do they provide a compatible presentation viewer on other platforms?

Now, for the alternatives…

Alternative 1: LibreOffice Impress

LibreOffice is a very popular open source office software. It’s free as in free beer, meaning you don’t have to worry about paying for it. Ever. It’s not a web app, so unlike many HTML5 alternatives you’ll have to download it. Fortunately, it’s available for every significant operating system out there so you shouldn’t have a problem running it whether your on Windows, OS X or Linux.

LibreOffice’s presentation tool, called Impress, comes with all the basic functionality you’re used to from slide authoring tools like PowerPoint and Keynote. You can save your presentation in LibreOffice’s own file format or export it to PDF or PPTX.
Although LibreOffice just celebrated its fourth birthday, Impress and the other office components have been around much longer (check out the history behind LibreOffice/OpenOffice).
If you’re looking for a free tool to completely replace PowerPoint (or other MS Office components), LibreOffice is probably your best choice.

More about LibreOffice Impress

Alternative 2: Google Drive – Slides

Google’s contribution to the presentation software sphere is integrated with Google Drive, their personal cloud storage service similar to DropBox. Google Slides is pretty much like PowerPoint, only it’s all in your browser. They also offer web based spreadsheet and document editing tools, making Google Drive a direct alternative to Microsoft’s web based Office 365.

Unlike Office 365, Google Drive is free as long as you have a Gmail/Google account. If you’re fine with your presentations being stored on Google’s servers, Google Slides is a good alternative to PowerPoint. No software downloads means you can access and edit your slides from any device with a modern browser and Internet connection.
For offline viewing, Google Slides supports exporting to PDF, PPTX and images. You can keep your presentations private or choose to share them online (through unique URLs), embed them on web pages and invite people to collaborate on your slides.

More about Google Slides

Alternative 3: Prezi

Prezi is known as the zooming presentation tool. It has been around for some years now and comes with a subscription based license model. It costs money, but you can use a crippled version for free. The free version will put a watermark on your prezis and you’ll be limited to non-private presentations.
Imagine a prezi as taking your PowerPoint slides and randomly placing them on a big canvas. Then draw a path between those slides in the order you wish to present and add some zooming effects. The result you get is a typical Prezi presentation. Professional Prezi presentations however take advantage of the spatial coherence between slides and use the zoom out (overview) vs. zoom in (details) features to better get across the message of the presentation.

Prezi offers both a desktop and a web based editor and lets you publish prezis online as well as export them to .exe./.dmg, .pdf and .prz (Prezis own proprietary format). The different export formats have different pros and cons; A self contained Prezi in .exe or .dmg format is portable, but can consume a lot of memory (1 GB is not unusual), while a Prezi in PDF loose all its zooming flair and .prz files require a special viewer to be installed.
If you’re tired of the linear slideshow concept and want to easily add some zooming effects to your presentations, Prezi is the right tool for you.

More about Prezi

Alternative 4: Apple Keynote for Mac

Keynote is Apple’s PowerPoint clone. In 2013, Apple redesigned Keynote with version 6.0, and made it free for anyone with a new iOS device or a recently purchased Mac. The product integrates well with iOS devices, allowing you to use your iOS phone or pad to control Keynote and view slide notes. Although very similar to Office PowerPoint, it lacks a few features. On the upside, the slide themes that comes bundled with the product look really good.

Although Keynote supports exporting to PowerPoint, not every transition and effect will look the same when played on a Windows PC. Its native .key format is proprietary and there are currently no presentation viewers available for .key files on Windows or Linux. If you’re a casual presenter, Keynote is probably good enough for you, but if you’re a professional speaker that talks at conferences and events (where PPT is the de-facto standard), I’d consider checking out Office PowerPoint for Mac.

More about Apple Keynote

BONUS: SlideDog – the presenter’s best friend

While not a PowerPoint alternative per say, SlideDog deserves a place in every presenters toolbelt. With SlideDog you can combine PowerPoints, Prezis, PDFs, and many more elements into one easy-to-create playlist. You never have to switch between different programs during your presentation and your presentation files show in their original formats, and display just like you’d expect them to. Once the playlist is loaded, your content plays back as though it’s just one seamless file.

SlideDog features “live slide sharing” meaning you can broadcast your presentations in real-time and let your audience follow your slides on their own devices. Send your participants a link to your online channel and with a click they’re in, watching from their own web browser. In the same channel they can answer polls and Q&A sessions that you’ve prepared in SlideDog. The results of any audience interaction will appear on the presenter’s screen. Additionally, SlideDog lets you control your presentation from any web-enabled device. You can use the SlideDog Remote app to switch between presentation files, change slides, pause videos, and more.

Download SlideDog for free and give it a try!