Open Office has a few presentation software application called Impress.  I have not used it so I cannot comment on quality, but see the link for a review..

http://www.presentationmagazine.com/is-open-office-impress-better-than-powerpoint-94.htm

I use SwishMax for presentations. it is lively and enlightens my audience even though it takes a lot of preparation time compared to the infamous PowerPoint.

Dear Fabrício, I still often use PowerPoint, including its tools such as animation. I often use Sway, a presentation tool when I prepare online assignments. Maybe I should use it more often for presentations. It creates the feel of a 'book' that one scrolls through. I also embed a link to Haiku Deck because I believe that you will find a number of people are using it.  Finally, I embed links to two post that provide information about further presentation tools.

http://www.makeuseof.com/tag/create-cloud-based-presentations-microsofts-powerpoint-destroyer-sway/

http://www.freetech4teachers.com/2012/09/create-beautiful-presentations-with.html#.V1Lg277S7IV

http://creativeoverflow.net/15-impressive-tools-for-creating-beautiful-presentations/

http://www.ragan.com/Speechwriting/Articles/46851.aspx

Cool! Thank you guys for so many useful resources!

I also use another tool to create figures for presentations papers and so on. 

www.mindthegraph.com

Have you heard about? Many people are using it, mainly in US.

www.mindthegraph.com