Ghostscript vs Postscript: What are the differences?

Introduction

This Markdown document provides a comparison between Ghostscript and Postscript, highlighting the key differences between the two.

1. Language Specification: Ghostscript is a powerful rendering engine and interpreter for the PostScript language and the PDF file format. It interprets PostScript code and converts it into a readable format. On the other hand, Postscript is a page description language developed by Adobe Systems Incorporated. It is used to describe the appearance of a printed page and includes commands for drawing objects, applying transformations, and manipulating images.

2. Responsibilities: Ghostscript is responsible for interpreting PostScript files, executing their instructions, and rendering the output on various display devices or printers. It enables the conversion of complex PostScript documents into different formats, such as PDF, JPEG, or PNG. Postscript, on the other hand, is responsible for describing the content of a printed page, including text, images, and graphics. It defines the layout and appearance of the final document.

3. Compatibility: Ghostscript provides compatibility for a wide range of PostScript versions, allowing it to handle both older and newer PostScript files. It ensures backward compatibility and is capable of executing most PostScript instructions. Postscript, however, refers specifically to the language itself and its specifications. Different versions of Postscript may include additional features or improvements over previous versions.

4. Extension Support: Ghostscript supports additional features, not present in the PostScript language, which makes it a versatile tool for document rendering and conversion. These extensions include support for PDF files, various image formats, color management, and font handling. Postscript, on the other hand, primarily focuses on defining the appearance of a printed page and does not include these additional features.

5. Usability: Ghostscript provides a command-line interface that allows users to interact with the program using text commands. It can be easily integrated into various software applications or used as a standalone tool. Postscript, conversely, is not directly interactable by users. Instead, it serves as a basis for printer drivers and other software applications that generate PostScript files.

6. Development and Licensing: Ghostscript is an open-source software, which means it can be freely used, modified, and distributed by anyone. It benefits from contributions from a global community of developers and has an active development cycle. Postscript, on the other hand, is a proprietary technology owned by Adobe Systems Incorporated. While the specifications are openly available, the development and licensing of PostScript-related software may involve licensing fees or agreements.

In summary, Ghostscript serves as an interpreter and rendering engine for the PostScript language, offering extended functionality and compatibility with various file formats. Postscript, on the other hand, is a page description language developed by Adobe, specifically focusing on defining the appearance of printed pages.