The Gothic horror genre was late eighteenth-century, from the works of writers such as Horace Walpole (in his The Castle of Otranto, 1764), Matthew "Monk" Lewis in his The Monk, William Beckford (in his Vathek), and Mrs Radcliffe (notably her The Mysteries of Udolpho). This genre of haunted abbeys and wicked scheming was vigorously mocked by comic writers such as Jane Austen in Northanger Abbey and Thomas Love Peacock in Nightmare Abbey, both published almost at the same time.
Webster's example of the Gothic typeface has been lost in the transfer to e-Webster, but is in any case incomplete. Gothic means either of two typefaces: (i) the ornate mediaeval one also called Black Letter or Old English or Fraktur; and (ii) the square-cut sans-serif one also called Grotesque and formerly stone letter. The term is still used for Grotesque in America, and has rather dropped out of use in Britain.
The Gothic language is one of the earliest Germanic languages recorded. (A few runic inscriptions in very early Norse exist before it.) Much of the New Testament survives, the work of bishop Ulfilas (Gothic name Wulfila), who translated almost all the Bible into Gothic in the mid 300s.
The Goths might have originated in Scandinavia and passed through the island of Gotland off Sweden before beginning their wide migrations across Europe. It is in some ways slightly closer to Norse than to the more southerly Germanic languages such as German and English; but the dialectal divisions in Proto-Germanic are still disputed. The two Gothic peoples were the Ostrogoths and Visigoths, which look as if they mean East-Goths and West-Goths, but it is not completely certain that they do.
It was written in an alphabet invented by Ulfilas out of Greek, Latin, and runes. It contains symbols for TH, KW, and HW, and Ulfilas used the Greek habit of writing GG to indicate NG. The long I vowel was written EI, another influence from Greek. The groups AI and AU present problems: they arose from several different sources in older Germanic, sometimes long E and O, in other cases diphthongs. Traditionally philologists treated them separately, but they were probably both monophthongs by the time Ulfilas was writing.
It is much more archaic grammatically than other recorded Germanic languages (except those very earliest runes), preserving much of the Proto-Germanic inflexion intact. The o-class masculine ending is -s, as in fisks 'fish'. This comes from Proto-Germanic -az, corresponding to Latin -us and Greek -os. The only other language to keep this ending was Old Norse, as -r (modern Icelandic -ur, earliest runes -R with a different letter).
Here is a sample: Jah usgaggadin imma in wig, duatrinnands ains jah knussjands baþ ina qiþands: laisari þiuþeiga, hwa taujau ei libainais aiweinons arbja wairþau?
Iþ is qaþ du imma: hwa mik qiþis þiuþeigana? ni hwashun þiuþeigs, alja ains guþ. (Mark 10:17-18)
The numerals one to ten were ains, twai, þrija, fidwor, fimf, saihs, sibun, ahtau, niun, taihun.
A few words of Gothic were recorded in Crimea around 1560; the language must have died out not long after.
The standard work is Joseph Wright's Grammar of the Gothic Language from around 1900, but still in print with revisions and a must for students. If you're interested in Germanic languages you will also like a new book, Old English and Its Closest Relatives: A Survey of the Earliest Germanic Languages by Orrin Robinson. Or for a complete scanned version of Wright, among other resources see
http://www.ling.upenn.edu/~kurisuto/germanic/language_resources.html