Documentation
Installation
For Windows and Mac OS X, you can install Notatio Antiqua using the installers or the drag and drop dmg.
Under the Linuxes, you can install the deb and rpm packages using dpkg or rpm.
For all other operating systems (unsupported) you unfortunately have to compile from source.
Usage
Resources
If you want to learn using gregorio, there is a lot of information on the gregorio website