GroupDocs
GroupDocs is a web-based service for online document sharing, collaboration and management. You can easily and securely upload, convert, view, sign and compare any document format (PDF, DOC, DOCX, XLS, PPT, PPTX and many more) with your colleagues and business partners in the realtime without the need to install any software. All the typical file management operations like managing Folders, Copy, Move and Delete are supported. Also you can electronically sign documents by adding your signature and encrypting the document contents. The built-in drag & drop interface allows you to organize your files quickly where you can further create multi-page questionnaires for an easy document assembly.
