PDFio is a simple C library for reading and writing PDF files.

Use the Office File API to create thumbnail images for Excel, Word and PDF documents.

Use the Azure Key Vault API to sign a PDF document.

Implement a PDF viewer in an ASP.NET MVC web application.

Use a PdfGraphics object to add interactive form fields to a PDF document.

Extract the text of a PDF document and count the words' occurrences in a document text.

Customize print output and specify settings for a specific document page.

A pdf document toolkit which splits, extracts and merges specified pdf files. Deployed with Flask and accessible via Web UI.

Obtain a checked appearance name for a check box and specify the check box value.

Implement a custom signer based on the Bouncy Castle C# API and use a custom digest calculator to calculate a document hash.

Use the PDF Document API to embed XMP metadata in PDF documents.

Use the PDF Document API to rotate document pages and save the result.

Use the PdfDocumentProcessor to add a visual signature to a document.

Create a custom timestamp client based on the Bouncy Castle C# API.

Export a PDF document to multi-page Tiff and bitmap images.

Access and modify custom document properties.

Use the PDF Document API to create a document with graphics in code.

Extract the first page from a PDF document into a separate document.

Implement a PDF viewer in an ASP.NET web application.

Create an interactive form field (a list box field) and add it to a PDF document.

Remove markup annotations that meet a specific condition from document pages.

Use the PDF Document API to read comments (sticky notes) from a PDF document.

Add a link to a URI at the specified link area on a document page.

Use the PDF Document API to merge pages of two separate PDF documents into a single PDF document.

Use the PDF Document API to create, edit, add comments and remove PDF annotations.

Remove an interactive form field by its name from a PDF document.

Use the PDF Document API to obtain document bitmaps in code.

Create an interactive form field (a combo box field) and add it to a PDF document.

Remove all markup annotations from document pages.

This free consulting project uses Aspose.PDF for .NET and allows you to encrypt/decrypt a PDF document by applying a password and setting different privileges to it. It is also a representation of API usage under .NET Core Framework.