Academic Presenter is a free offline presentation software which enables users to prepare a special type of vector-based presentations. This unique software helps users to represents very huge graphs in addition to raster images, audios, and videos.
Impress, part of the Apache OpenOffice suite, is a presentation program similar to Microsoft Office Powerpoint . It does dual screen and linear presentations out of the box, but the free "Presenter Console" extension adds much better dual screen and non-linear presentation capabilities.
Impress works very well with existing Powerpoint files. It can save to various formats including Powerpoint, Open Document Presentation format, Flash (SWF) and PDF.