GroupDocs
GroupDocs creates easy to use, comprehensive online document management APIs for .NET, Java and Cloud, as well as a range of Cloud apps that improve document collaboration for organizations of any size. GroupDocs saves developers and end users time and money by offering a complete and powerful set of document management APIs allowing users to view, sign, annotate, compare, convert and assemble documents in a wide variety of formats, including Microsoft Word, Excel, PowerPoint and Visio, as well as Adobe Acrobat PDF and many image formats. Flexible workflows and easy-to-use, customizable user interfaces are part of the package.
Jugaad
RadaeePDF SDK is a great PDF rendering and manipulation tool for developers. If you develop mobile or desktop applications the RadaeePDF SDK framework is the "Swiss Army knife" to handle PDF files. More than 6,000 applications are running the SDK on Android, iOS and Microsoft Windows UWP.
Handsoncode
Handsoncode is a software development company based in Pomeranian Technology and Science Park in Gdynia, Poland. It provides consulting services and on-demand development