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Liblouis

The Liblouis software suite provides an open-source braille translator, back-translator and formatter for a large number of languages and braille codes. It is a set of libraries designed for use in any of a number of applications, both free and commercial. It is written in C so that it does not require a runtime environment and hence can be used in applications written in high-level languages such as Java and Python.

News

06 Jun 2025 Liblouis Release 3.34.0

This release brings significant improvements to various language tables, particularly for Classical/Biblical Hebrew where three main standards are now supported. We have a new table for Thai Grade 2 contracted braille, and substantial updates to Lithuanian braille tables. There are also improvements to Hungarian, Dutch, Norwegian, and Turkish tables. On the technical side, there’s new support for building macOS universal binaries and the pre-built html and plain text documentation is no longer packaged with the released tarball.

17 Mar 2025 liblouis joins the Software Freedom Conservancy

The liblouis project and Software Freedom Conservancy (SFC) are excited to announce that liblouis has joined SFC as a member project, with the goal of ensuring sustainability and a framework for long-term stewardship of the project. As a nonprofit home of liblouis, SFC will provide a home for fundraising, legal assistance, and governance that will benefit all users of the project.

03 Mar 2025 Liblouis Release 3.33.0

This release combines braille improvements with security enhancements. We have new tables for Coptic braille, Cuneiform transliteration and for Portuguese 6-dot computer braille. There are improvements to Dutch, Hungarian, the International Phonetic Alphabet, Norwegian and UEB. On the security side a lot of people have reported and fixed buffer overflows and other memory issues.

Braille translator and back-translator

Liblouis is an open-source braille translator and back-translator named in honor of Louis Braille. It features support for computer and literary braille, supports contracted and uncontracted translation for many languages and has support for hyphenation. New languages can easily be added through tables that support a rule- or dictionary based approach. Tools for testing and debugging tables are also included. Liblouis also supports math braille (Nemeth and Marburg).

Liblouis has features to support screen-reading programs. This has led to its use in numerous open-source and proprietary screenreaders such as NVDA, Orca, BrailleBack and JAWS. It is also used in some commercial assistive technology applications for example by ViewPlus.

Liblouis is the translator of choice for Benetech’s Bookshare, providing braille access to more than 350,000 books to members worldwide. Bookshare currently offers titles in braille in more than a dozen languages, with the ability to quickly add new languages as translation tables become available.

Liblouis is based on the translation routines in the BRLTTY screenreader for Linux. It has, however, gone far beyond these routines. In Linux and Mac OSX it is a shared library, and in Windows it is a DLL.

Liblouis is free software licensed under the GNU Lesser GPL.

Language bindings

The software has interfaces to a number of programming languages. There are known bindings to C, Python, Java and Javascript.

Braille formatter

Liblouisutdml is an open-source braille formatter. The formatting can be configured via a style sheet. By incorporating Liblouis it provides the capability of translating any XML or plain text file into properly transcribed, embosser-ready braille. This includes translation into grade two, mathematical codes, etc.

Liblouisutdml is free software licensed under the GNU Lesser GPL.

Braille production

There are several braille production systems based on Liblouis and/or Liblouisutdml.

BrailleBlaster, a joint project between ViewPlus Technologies, American Printing House for the Blind and Abilitiessoft, is aimed at hands-on production where every detail of the Braille is controlled via a graphical user interface.

DAISY Pipeline, backed by the DAISY Consortium, is aimed at automated, hands-off, high-volume production on the server.

Sao Mai Braille, a rich text editing and Braille translation software for Windows, is developed by Sao Mai Center for the Blind, a non-profit organization based in Vietnam.