aspose.slides.via.java
A powerful library for manipulating and converting PowerPoint (PPT, PPTX, PPS, POT, PPSX, PPTM, PPSM, POTX, POTM), ODP, ODS, CSV, TXT, PNG, EMF, JPG, JSON and HTML files.
@groupdocs/groupdocs.watermark
Create and apply watermarks on PDF, Word, Excel, PowerPoint, and image files, including JPG and PNG. Fast, powerful, and easy-to-use watermarking tool.
@groupdocs/groupdocs.viewer
Powerful, high-performance and cross-platform library that allows you to build desktop and web file viewer applications.