In origin, it is not a single coherent work, but a collection of independent commentaries which were revised over time.
The Glossa ordinaria was a standard reference work into the Early Modern period, although it was supplemented by the Postills attributed to Hugh of St Cher and the commentaries of Nicholas of Lyra.
[1] The main impetus for the composition of the gloss came from the school of Anselm of Laon (d. 1117) and his brother Ralph.
The Patrologia Latina, volumes 113 and 114, contain a version of the glossa which, as well as being misattributed to Strabo, represents a later manuscript tradition.
Many important works would also have their own glossa ordinaria, such as that of Accursius for Justinian's Corpus or that of Johannes Teutonicus Zemeke and Bartholomew of Brescia of Gratian.