APL was originally conceived as an improved notation for mathematics, unifying a variety of fields and concepts. This effort is sometimes portrayed as a failure for not being universally adopted wholesale, but some of its ideas did influence popular usage, including the adoption of APL's ⌊ (floor) and ⌈ (ceiling) symbols, as well as those names for the operations.
Not to mention Scheme (and Scala and many other languages) primitives such as “take” and “drop” and even “iota”. In addition, many of the achievements cited in this article flow from the fact that APL\360 was one of the first highly-interactive systems that were widely available.