Prawn

Prawn is an open-source PDF generation library for Ruby. It lets developers create PDF documents programmatically from application code rather than editing existing PDFs. Typical users include Ruby and Rails developers building invoices, reports, labels, and other server-generated documents.

It focuses on layout and document creation: text, tables, images, basic graphics, and page-level control. A distinguishing trait is that it is a Ruby-native library widely used for code-driven PDF output in web applications, rather than a desktop editor or a full PDF manipulation suite.