Last modified 11 months ago Last modified on 04/11/16 17:40:28

UTRRS (Unicode Text Rendering Reference System)

Unicode Text Rendering Reference System" (UTRRS) is an web-based Application which has been developed by Red Hat Inc. under an Open Source license - GNU GPLv3 (reference given below), which compare a reference image of a text character, word or phrase with another image of the character, word or phrase that was rendered by a text rendering engine. Differences between the reference image and the rendered image may be recorded for subsequent analysis. This is an web based application. Performance of a text rendering engine producing text according to typographical rules applicable to a natural language can be evaluated by one with no knowledge or ability to read the natural language.

This Application has been designed and developed for Indic Locales as of now. We will be adding a few more Indic locales in the near future as per our short-term plan and we have long term plan for adding CJK and other supported locales of different countries also.

Currently this application is under continuous enhancement process in terms of Feature enhancement, Locales enhancement and Resource enhancement in terms of more community contributions.

This Application relates to internationalization of computer interfaces. More specifically, the Application relates to testing complex text layout ("CTL") rendering systems. A system to test complex text layout ("CTL") rendering engines. The system may be used to assist a human in performing a series of tests, or it may be used to automatically test rendering engines and flag characters and character sequences that may have been rendered incorrectly.

The system does not require its users to be familiar with the language being rendered. Procedures are strictly visual, and do not require any semantic comprehension. This application is platform independent.

The current standard of Code-point Reference Images is developed according to the Unicode-5.1 Character Set. Referring the Unicode Website here : Unicode 5.1.0

For the Glyph Substitution (GSUB) and Glyph Positioning (GPOS), a Reference Image of composed characters has been generated, following the codepoint standard, mentioned in Unicode-5.1 Character Code Chart. Reference here : charts

This Open Source Project has been licensed under GNU GPLv3 License and its license text can be found at the website GNU GPLv3 License


Approximately 7000 character sequences has been developed so far, in this Application and still counting. As the locale coverage increases, the number of character sequences will also be increased in future. It also includes the extensive research on Language Technology, Understanding of Rendering Engines and how it works, Internationalization Methodology and Procedures, In depth understanding of character rule set for each of the languages, Rules of composite character set and grammars of various languages, Testing methodologies for Internationalizations and Localizations, Unicode Character set Understanding, etc.

We deserve and obey your valuable feedback on this!!

Current Languages Covered

  • Bengali
  • Gujarati
  • Hindi
  • Punjabi
  • Tamil

Languages support in process

  • Assamese
  • Kannada
  • Malayalam
  • Marathi
  • Oriya
  • Telugu
  • Sinhala
  • Urdu

For a complete list of local wiki pages for navigation, see


To grow further with this project, here we announce the defined responsibilities of the current project members. There are two wings of current UTRRS Project currently defined. The first one is UTRRS-data, and the second one is UTRRS-web.

Primary Roles and Responsibilities :

Amanpreet Singh : Mainly responsible for maintenance of the UTRRS-data part of the project.

Ankit Patel : Primarily responsible for UTRRS-web part and development part of it, along with Anish.

Anish Patil : Recently Joined UTRRS team and interested in web development. He will assist Ankit.

Parag Nemade : Provide feature requests, act as an internal customer and report bugs.

Pravin Satpute : Provide feature requests, act as an internal customer and report bugs. Co-ordinate with external

stakeholders and act as a prime bridge between Government stake-holder and internal one.

Satyabrata Maitra : Leading and supervising this project from this point and onwards. Responsible for all the project

related issues, task management and allocation, reporting and managing tickets or issues, coordination between team members, define time-lines upon discussion with all the team members, decision-making etc. Along with this, I will assist Amanpreet on data management including addition, insertion, deletion and modification and any kind of transaction on our data part.

Further announcement on role-specific tasks and responsibilities in micro level will be published upon further discussion.

You can checkout the source code as

Read: git clone

Write: git push ssh:// master

UTRRS Demo on RH Cloud (for reference)

UTRRS Introduction slides

The code can be browsed here

Bugs can be reported at newbug

Mailing list

UTRRS Developers:

UTRRS commit:


UTRRS Web commits: