The name Migne has been very important to Medieval scholars since -- ta-daaaa! -- 1841.
This is Jacques Paul Migne, 1800-75,
a French priest and a publisher of a series of hundreds of volumes -- huge volumes. Huge inexpensive volumes -- of Latin Medieval writing, and another series containing hundreds more volumes, of Greek Medieval writing. The Latin series, the Patrologia Latina, was begun in 1841. Here's volume 41. Volume 32-47 contain the complete works of Augustine. The series is numbered chronologically by the dates of the authors, from Tertullian in volumes 1 and 2 to Pope Innocent III in volumes 214-217. (Volumes 218-221 are indices.)
Medieval scholars today -- Migne called his series an ecclesiatical series rather than a Medieval one, but Medieval Latin almost always means Latin written by clergy, so, po-TAY-to, po-TAH-to, I say! -- are gradually replacing Migne's inexpensive volumes of Medieval source materials in Latin and Greek with extremely expensive ones. I mean, you wouldn't believe how much they charge for these newer editions. Anyway, it's all very splendid despite the amazing prices. (PS: Okay, actually, there are a few publishers offering brand-new editions of Medieval Latin texts at pretty reasonable prices. There are the Toronto Medieval Latin Texts, the Medieval and Renaissance Texts and Studies or MRTS, and the edition of Domesday Book published in many small paperback volumes by Phillimore and Co, Ltd. All of them actual bargains. And no doubt there are still other exceptions to the extremely-expensive rule, before we even get to the wide, wide topic of photographic reprints of pre-copyright items such as, for instance, Migne. Some of those reprints are quality products and some are crap. That topic deserves its own blog post.) (Some of these recent volumes smell like church pews. Or maybe it's the hymnals in those pews that give the pews that smell.)