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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

07 Jun 2022 Liblouis Release 3.22.0

This is a major release. On the Braille tables side there is a new table for German grade 2 with capitalization and there are updates to the Dutch, German Hungarian, Punjabi, Russian, UK Braille Computer Notation and Slovak tables. Christian added a new opcode to indicate the end of a number where the number doesn’t end at a space character. Last but not least Samuel, Martin and Han have put a lot of work into checking for and fixing memory problems.

10 May 2022 Emacs mode for editing liblouis tables

Good news for those of you who are editing liblouis tables using Emacs. There is now a liblouis mode that helps by providing syntax highlighting and other helper functionality.

08 Mar 2022 Liblouisutdml Release 2.11.0

This minor Liblouisutdml release adds support for liblouis 3.20 and up.

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.