- History and Development
- PDF was created by Adobe in 1992 as a document format independent of software
- Started as "The Camelot Project" initiated by John Warnock in 1991
- Became ISO standard in 2008, latest edition published in 2020
- Technical Features
- PDF combines PostScript with declarative programming language
- Supports vector graphics, raster images, text, and interactive elements
- Uses ASCII characters and COS object structure format
- Allows transparency since version 1.4
- Security and Accessibility
- Can be encrypted with user and owner passwords
- Supports digital signatures and usage rights
- Enables accessibility through tags and optional content groups
- PDF/UA standardizes accessibility features
- Interactive Features
- Supports rich media including images, audio, and video
- Includes AcroForms and XML Forms Architecture for forms
- Allows file attachments and metadata storage
- PDF 2.0 introduced extensible metadata support
- Limitations
- Larger file sizes compared to traditional formats
- Limited flexibility compared to full-featured PostScript
- Security vulnerabilities discovered in 2019 and 2021