From Batchwork Software:
Batch PPT TO PDF Converter is a PowerPoint PPT/PPTX to PDF Batch Converter can convert PowerPoint PPT(X) to PDF (Portable Document Format) easily. Batch PPT TO PDF Converter supports powerful search for lots of files. A PDF publisher for PowerPoint. Batch PPT TO PDF Converter supports project and command line. Batch PPT TO PDF Converter has a friendly GUI so it is used very easily. Batch PPT TO PDF Converter Drag and Explorer Context supported. Batch PPT TO PDF Converter supports a efficient Multi-Thread conversion engine. So you could control the conversion action very easily. You can stop or pause and continue it in any time. You can save your conversion work in a project file (.batch-ppt2pdf) for re-use. You can run the batch-ppt2pdf project in Microsoft Windows Explorer or command line directly.
Version: Batch PPT To PDF Converter 2011.3.403.1390
Simple program which does exactly what it says. Quick conversion without errors. Used to convert university lectures for use on the kindle
Slight Nagware, Doesn't convert some in the queue asking for registration but re-adding these skipped files will get them converted so only a problem for HUGE batches. File names of converted files are watermarked but not the contents.
Quick, easy to use, small download, nagware is annoying but can be worked around.