Nikoli (ニコリ) is a Japanese publisher that specializes in games and, especially, logic puzzles. It is also the nickname of a quarterly magazine issued by the company (whose full name is Puzzle Communication Nikoli). Nikoli became prominent worldwide with the popularity of Sudoku.
The name 'Nikoli' comes from the racehorse who won the Irish 2,000 Guineas in 1980; the president of Nikoli, Maki Kaji, is fond of horse-racing and betting.
Nikoli's claim to fame is its vast library of "culture independent" puzzles. In general, there has been a trend toward "world audience" marketing of games and puzzles; that is, they should function independent of language and culture. (An example of a language/culture-dependent genre of puzzle would be the crossword, which relies on a specific language and alphabet.) For this reason, German-style board games are often spare in words and heavily illustrated, and Japanese puzzles are often purely logical, and often numerical. There is much diversity among modern societies when it comes to alphabet and grammar, but all use the same numerical system.
Nikoli's second most-popular puzzle, Sudoku, was popularized in the English-speaking world circa 2005 (although it should be noted that Sudoku is originally an American invention); its most popular puzzle is the crossword. The magazine has invented several new genres of puzzles, and introduced several new games to Japan.
