A free file format is a file format that is both (1) published so that anyone can read and study it in its entirety and (2) not encumbered by any copyrights, patents, trademarks or other restrictions so that anyone may use it at no monetary cost for any desired purpose. Such specifications are usually maintained by a non-commercial standards organization.
A file format is any specific way of encoding digital data to create a file. A file is a named collection of related data that appears to the user as a single, contiguous block of information that can be retained in storage (e.g., a hard disk drive, CDROM and magnetic tape) and accessed by its file name.
The term open format is commonly used to mean free format. However, it is useful to make a distinction between the two, similar to that between the terms open source software and free software. Open source software is software for which the source code is made freely available for anyone to read and study but for which there may be restrictions on its use. Source code is the original version of the software as written in a human-readable form by programmers and is analogous to the detailed specification of a file format.
Free software is software for which not only is the source code freely available but also for which the source code (and its compiled binaries) can be used for any desired purpose without restrictions (including copying, modifying and redistributing it its original or modified version). Thus, open format should refer to any format that is published for anyone to read and study but which may or may not be encumbered by patents, copyrights or other restrictions on use.
Proprietary file formats are file formats that are controlled by a single company and thus are not entirely free. The extent of restriction depends on the company and its policies. In many cases the detailed specifications are kept secret and other companies are prohibited from using them, such as is common with Microsoft products. In some cases, other companies may be licensed to use proprietary formats in return for monetary payments. Open formats are also a type of proprietary format.
A free file format is a type of free standard, which is is any set of specifications that is likewise both published and available for anyone to use at no monetary cost and without restrictions.
There are several important advantages of free standards as compared with their proprietary counterparts. One is that they facilitate competition, and thereby reduce costs and inconvenience for users. A second is that they provide portability of data among various types of computers, operating systems and application programs. A third is that they guarantee long-term access to data without uncertainty regarding legal rights or technical specifications.
Government agencies in various countries have become increasingly interested in the use of free file formats as an alternative to the widely used Microsoft formats for public documents. One reason is the growing viability of Linux, OpenOffice and other free software and the rapid increase in awareness of the advantages of such software. Another is the increasing difficulty of accessing data that was saved in older file formats that are no longer being supported by software developers. Moreover, there is a growing realization that this problem will intensify as commercial software vendors continue to bring out new or revised formats that lack full backward compatibility with earlier formats.
There is a close relationship between free software and free file formats, although there are some important differences. The default file formats for free software programs are free formats, although such programs can also use and save data in proprietary formats in order to have compatibility with commercial software. Many proprietary programs also can use free file formats, although they tend to not be the defaults.
For example, OpenOffice, which is a full-fledged, free software office productivity suite that includes word processing, presentation, spreadsheet and drawing programs, saves data by default in OpenDocument Format (ODF), which is the first free file format that was developed and approved by an independent standardization body. It can also open and save data in other free formats, including PDF (portable document format), HTML, XML, XHTML and plain text. In addition, OpenOffice can open and save data in various proprietary formats, including all of the common Microsoft formats.
PDF, which was introduced by Adobe Systems in 1993, has been a free format for some time because the company has published all of the details of the standard and does not have restrictions on its use. Adobe has recently been making efforts to further strengthen recognition of PDF as a free format by hiving it certified by the Geneva-based ISO (International Standards Organization), as an independent standard. PDF has been very profitable for Adobe because of the widespread acceptance of this format, which is in large part due to its free nature, and because of Adobe's domination of the market for programs to create PDF format documents.
Examples of free file formats for images include PNG (portable network graphics) and SVG (scalable vector graphics). The former was developed because a company (Unisys) claimed to own patents on the LZW data compression algorithm that is used by the popular GIF (graphics interchange format) format and was attempting to force corporate users to pay royalties. An example of a free file format for audio is Ogg, which was developed as an alternative to MP3 because the latter is encumbered by patents. Examples of free formats for data compression include bzip2 and gzip.
Created February 11, 2007.