About OpenDocument

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OpenDocument Overview

The OpenDocument Format (ODF) is an open XML-based document file format for office applications to be used for documents containing text, spreadsheets, charts, and graphical elements. The file format makes transformations to other formats simple by leveraging and reusing existing standards wherever possible.

As an open standard under the stewardship of OASIS, ODF also creates the possibility for new types of applications and solutions to be developed other than traditional office productivity applications. ODF is defined via an open and transparent process at OASIS and has been approved unanimously by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) as an international standard in May 2006. It is available for implementation and use free of any licensing, royalty payments, or other restrictions.

From a technical point of view, ODF is a ZIP archive that contains a collection of different XML files as well as binary files like embedded images. The use of XML makes accessing the document content simple because content can be opened and changed with simple text editors if necessary. In contrast, the previously used binary file formats were cryptic and difficult to process. The ZIP compression guarantees relatively small file sizes, in order to reduce file storage and transmission bandwidth requirements. ODF was the first broadly used document file format that used the concept of a ZIP package containing different XML files.

ODF uses the same set of XML files for different application types. In addition, definitions for elements like tables are consistent across application types as well. The OpenDocument format has a long tradition of openness. The first work on the file format started as early as 1999. Right from the beginning ODF was designed as an open and implementation neutral file format. The open specification process started in 2000 with the foundation of the OpenOffice.org open source project and the community efforts within its XML development project. An even higher level of openness was established in 2002 with the creation of the OASIS Open Office Technical Committee (TC).

Many organizations and companies are participating the ODF specification process. In addition, a growing number of applications implement the OpenDocument file format.

The OpenDocument Format was designed to be vendor neutral and implementation agnostic. In order to simplify transformations and to maximiz interoperability, the format reuses established standards like HTML, SVG, XSL, SMIL, XLink, XForms, MathML, and Dublin Core. ODF files of different application types (e.g. word processor, spredsheet) include the same set of XML files within the ZIP packages.

Features and benefits

Feature Benefit
OASIS standard Open, transparent specification process with multi-vendor participation
Approved by ISO as ISO/IEC 26300 Well known and broadly accepted standard
ISO standard Relax-NG schema types (ISO/IEC 19757-2:2003) Well known and broadly accepted standard
Supported by multiple applications Choice between free open source and commercial implementations including OpenOffice.org, StarOffice, KOffice, IBM Workplace, Textmaker, Abiword/Gnumeric, Google Writely, and AjaxWrite.
Broad industry support ODF guarantees long-term viability. The OASIS ODF TC, the OASIS ODF Adoption TC, and the ODF Alliance include members from Adobe, BBC, Bristol City Council, Bull, City of Largo, Corel, EDS, EMC, GNOME, Google, IBM, Intel, KDE, Novell, Oracle, Red Hat, Software AG, and Sun Microsystems. As of June 2006 the ODF Alliance has already more than 300 members.
Shipping products since September 2005 ODF files can already be created and used today. The first products with ODF support started shipping in September 2005.
Free open source “reference” implementations ODF is supported by multiple free open source office applications including OpenOffice.org, KOffice and Abiword/Gnumeric. OpenOffice.org, for example, is developed by large community including vendors like Sun Microsystem, Novell, Intel, and Red Hat. Due to the availability of the source code, support for additional platforms or languages can be added by anyone.
ODF implementations available for all major desktop platforms Applications with ODF support are available for Microsoft Windows, Linux, the Solaris OS, Apple Mac OS X, and FreeBSD.<
Open standard W3C XForms technology is used for forms The forms concept integrated into ODF is based on the W3C standard XForms which is supported by multiple applications and vendors.
Reuse of existing standards where possible Instead of trying to reinvent the wheel and to make interoperability as simple as possible, ODF reuses established standards like HTML, SVG, XSL, SMIL, XLink, XForms, MathML, and Dublin Core.
Very mature The first work for the ODF file format started as early as 1999 (see the ODF history).

Why an open file format matters

In a world where paper documents increasingly get replaced by electronic records, long term access to the data becomes critical. This is especially the case for legal contracts and government documents which stay valid and relevant over decades, or even centuries.

Like paper and pens have been available from multiple vendors, and not just one single source, document file formats and the applications creating these file formats need to be supported by and available from multiple vendors. This guarantees long-term access to data, even if companies disappear, change their strategies or dramatically raise their prices. 

Open standards that are equally accessible and do not favor one particular vendor, help maintain a diverse ecosystem of vendors. This as well causes competitive pricing, thus ensuring the best use of money from investors or tax payers.

Open standards also lower the barrier of entry, allowing new companies to join the ecosystem. For example, the SQL standard for relational databases allowed the emergence of various implementations including free open source and very specialized high-end database management systems. As long as only standard SQL features are used, database management systems can be exchanged without much effort. Vendor lock-in only happens based on special features not included in the SQL standard. Thus, vendor lock-in becomes a voluntary choice, not a mandatory one.

In the case of public documents provided by governments to their citizens, it is also important that no citizens, or at least as few as possible, get excluded from data access. For example, nobody should be forced to buy software from one specific vendor or for one specific operating system platform. Public data should be accessible to citizens independent off their income and their physical abilities.

Assistive Technologies

Assistive technologies are comprised of hardware and software offerings that serve the needs of persons with disabilities. These include screen readers and screen magnifiers for the blind and visually impaired persons; speech recognition for persons with mobility impairments; and Braille translation and formatting facilities to automate the process of conversion from regular print to braille (and vice versa). Solutions are also available for individuals with color blindness, cognitive learning disabilities, and varying degrees of paralysis (mobility) impairment.

Current ODF assistive technologies include:

See also:

- OpenDocument Accessibility FAQ
- OASIS OpenDocument Accessibility Subcommittee.

Accessibility FAQ

Review answers to frequently asked questions on OpenDocument Accessibility below. Post new questions and additional comments at the FAQ Forum.

How was accessibility addressed in OpenDocument v1.1?

The changes needed to make OpenDocument 1.0 accessible were relatively minor. The OASIS OpenDocument Accessibility Subcommittee did a gap analysis of v1.0 based on these criteria:
  • Support for W3C Web Content Accessibility Guidelines 1.0
  • Interoperability with assistive technologies
  • Preservation of structural semantics 
  • Increased usability of presentations over that available in today's office document formats
As OpenDocument v1.0 was largely based on W3C standards, the required changes were minor. They included:
  • Alternative text for non-text objects 
  • Proper association of captions to captioned content
  • Encoding of pagination information
  • Preservation of table semantic structure imported from other file formats
  • Proper encoding of authored table header content
  • Author-defined logical navigation of page objects in presentations
  • Provision of alternative text hints for hyperlinks
OpenDocument version 1.1 adds alternative text to document elements such as drawing objects and image map hot spots; preservation of structural semantics such as headings in tables: and associations between drawngs and their captions. The OASIS OpenDocument Accessibility Subcommittee took the opportunity to provide not only short alternative descriptive text but also lengthy descriptions for the same objects should additional help be needed for users who are blind, low vision, or who suffer from cognitive impairments. To improve the usability of presentations, OASIS also added the provision for the author to supply a keyboard navigation order. Users who are blind may be confused when accessing a slide because the keyboard navigation order does not match the visual flow of the slide.

Who participated in making OpenDocument v1.1 accessible?

The OASIS OpenDocument Accessibility Subcommitee was formed in January 2006. Participating in this effort are topic accessibility experts from Design Science, IBM, the Institute for Community Inclusion, the U.K.'s Royal National Institute for the Blind, and Sun Microsystems, as well as several unaffiliated individual experts.

Can OpenDocument be converted to DAISY book format?

Yes, The U.K.'s Royal National Institute for the Blind is building a DAISY talking book converter for OpenDocument v1.1 rich text documents.

How well do OpenDocument applications address the needs of people with disabilities?

While OpenDocument v1.1 includes a number of specific improvements for accessibility, it's important to note that many of the concerns around accessibility have to do with the applications that implement the OpenDocument format.  This includes questions about the built-in features of OpenDocument applications that meet the needs of people with disabilities, and questions about how well OpenDocument applications work with specialized assistive technology applications used by people with more severe disabilities.

To improve support for assistive technologies on the Windows platform, IBM donated an extension to Microsoft's Active Accessibility API to the Free Standards Group (Now the Linux Foundation) which was designed to provide advanced access to office applications and expose  all the accessibility features of OpenDocument 1.1. This API, called IAccessible2, was designed with the help of Freedom Scientific and GW  Micro during its implemenation in support of OpenDocument v1.1 in the upcoming  Notes 8 Productivity Editors. Furthermore, IBM worked with assistive technology vendor Freedom Scientific to ensure their office suite implementation of the ODF 1.1 specification worked well with assistive technologies.

Also on Windows, the OpenDocument applications StarOffice and OpenOffice.org already work with the ZoomText screen magnifier from Ai Squared.

On the UNIX platform, StarOffice and OpenOffice.org already work very well with the open source UNIX assistive technologies.  This includes the Orca screen reader/magnifier used by people who are blind or have significant visual impairments, the GNOME On-screen Keyboard which provides rich support for people with a variety of physical impairments, and Dasher, and innovative alternate text entry system used by people who can move only their head or eyes.

How can implementors ensure their OpenDocument applications are fully accessible?

The OASIS OpenDocument Accessibility Subcommittee is developing a guidelines document to help implementers create OpenDocument applications that are fully accessible. More information on this will be posted at the Subcommittee's homepage.

Are OpenDocument accessibility features preserved by applications that export to other file formats?

This depends on the application. StarOffice and OpenOffice.org, for instance, make full use Adobe PDF tags for accessibility when OpenDocument files are exported to PDF, so long as the user selects the "Tagged PDF" option.