History of the Gregorio project
The Gregorio project was born in 2006 at TELECOM Bretagne, a graduate engineering school in France. It was at first a student project of six months duration, supervised by Mr Yannis Haralambous, developer of Omega. When the project was done, Élie Roux decided to continue the project on his own and to develop it under GPL.
From the outset the goal of the project has been to create a graphical interface for the monks of the Abbey of Sainte Madeleine du Barroux so that they could use a gregorian font. This font, Gregoria, is a professional font designed by Elena Albertoni, a typographer and graphic designer. Due to licence issues, however, it was decided that the project would have its own font called gregorio.
At the end of 2006, a new developer, Olivier Berten, joined the project and created its OpusTeX component (deprecated since). By April 2007, Gregorio had reached a certain maturity and could start to be used, at least through its command line interface, as a preprocessor for OpusTeX. A project page was created at gna.org (now superceded by this site).
During a three-month internship, starting in April 2008, at the Monastero di San Benedetto, in Norcia (Italy), Gregorio made considerable progress and its own output named GregorioTeX started to be usable.
After a period of ups and downs in development, Gregorio reached some stability and popularity. A major step was taken when code repository was migrated to GitHub in June 2014. This migration made contributions much easier and sped up development by a considerable amount. As a result, new developers have joined the team, the develoment process improved, bugs decreased and output improved dramatically, and an impressive amount of new features have been implemented. One of the most impressive is adiastematic St Gall notation through nabc.
With all these changes, many began to consider Gregorio to have better output than documents produced by hand, resulting in its adoption by many Abbeys and large projects. These adoptions are leading in turn to even more improvements. The most impressive adoption is by Solesmes, using Gregorio for their future books!
2016 should see Gregorio integrated into TeX Live, easing the installation and leading to a possible inclusion in Overleaf. To prepare for this milestone a very demanding effort to track bugs and test everything was undertaken, leading to Gregorio being very carefully tested and improved.