draw.io - Online diagramming application
Photostage - Quickly and easily combine photos and videos with a narration or soundtrack using PhotoStage slideshow software. Free slideshow maker download for Mac & PC.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
ProShow - ProShow is a dedicated tool for creating slide shows from your photos, video and music.
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.
SmartSHOW 3D - SmartSHOW 3D is pro-level slideshow software with a powerful 3D animation engine.