Tengwar

Origin

J.R.R. Tolkien created many languages throughout his life. He wrote in one of his letters that the tales of Middle-earth (The Hobbit, The Lord of the Rings, The Silmarillion, etc) grew from these languages, rather than the languages being created for use in the stories.

Tolkien also created a number of different alphabets to write his languages - Tengwar, or Feanorian letters, is the one which appears most frequently in his work. The way the vowels are indicated in Tengwar resembles Tibetan and other Brahmi-derived scripts.

Notable features

Written from left to right in horizontal lines.
Tengwar is written is a number of different ways known as "modes". For example there is a Quenya mode, a Sindarin mode and even an English mode. The phonetic values of the consonants (tengwa) and the ways vowels are indicated varies from mode to mode.
Vowels are indicated by diacritics (tehtar) which appear above the consonant which precedes them (in Quenya mode) or above the consonant which follows them (in Sindarin mode). When vowels stand on their own or come at the beginning of a word, the diacritics appear over a special vowel holder. Long vowels are always attached to a vowel holder.
Consonants are doubled by adding a wavy line below them.
When followed by a vowel, the letters /s/ /ss/ and /r/ are written with the tengwa silme nuquerna, esse nuquerna and rómen respectively. Otherwise these letters are written with the the tengwa silme, esse and óre.
When the letter /s/ follows another consonant it is written with a little downward hook.

Used to write

A number of different languages of Middle-Earth, such as:

Quenya, Qenya or High-Elven, the most prominent language of the Amanya branch of the Elvish language family. Tolkien complied the "Qenya Lexicon", his first list of Elvish words, in 1915 at the age of 23 and continued to refine the language throughout his life. It is based mainly on Finnish, but also partly on Greek and partly on Latin.

Sindarin, the language of the Grey-elves or Sindar. Tolkien based Sindarin on Welsh and originally called it gnomish.

Sylvan, Westron, etc

Tengwar can also be used to write English, Welsh, Scottish Gaelic, Spanish, Swedish, Polish, Esperanto and a variety of other languages.