Credits > Intellectual Property

The architecture of this component is based on the "PDF Reference" document, third edition, published by Adobe. In this reference, page 6, Adobe gives copyright permission under the restriction that files are created which conform the Portable Document Format. In conformance with the reference we include the respective chapter here:

The general idea of using an interchange format for electronic documents is in the public domain. Anyone is free to devise a set of unique data structures and operators that define an interchange format for electronic documents. However, Adobe Systems Incorporated owns the copyright for the particular data structures and operators and the written specification constituting the interchange format called the Portable Document Format. Thus, these elements of the Portable Document Format may not be copied without Adobe’s permission.

Adobe will enforce its copyright. Adobe’s intention is to maintain the integrity of the Portable Document Format standard. This enables the public to distinguish between the Portable Document Format and other interchange formats for electronic documents. However, Adobe desires to promote the use of the Portable Document Format for information interchange among diverse products and applications. Accordingly, Adobe gives anyone copyright permission, subject to the conditions stated below, to:

• Prepare files whose content conforms to the Portable Document Format

• Write drivers and applications that produce output represented in the Portable Document Format

• Write software that accepts input in the form of the Portable Document Format and displays, prints, or otherwise interprets the contents

• Copy Adobe’s copyrighted list of data structures and operators, as well as the example code and PostScript language function definitions in the written specification, to the extent necessary to use the Portable Document Format for the purposes above

The conditions of such copyright permission are:

• Software that accepts input in the form of the Portable Document Format must respect the access permissions specified in that document. Accessing the document in ways not permitted by the document’s access permissions is a violation of the document author’s copyright.

• Anyone who uses the copyrighted list of data structures and operators, as stated above, must include an appropriate copyright notice.

The PDF Engine further uses the public zlib, the Independent JPEG Group's JPEG and RC4 routines. It also uses the LZW algorithm for decompression.