APL
Array-oriented language using a unique notation of mathematical symbols — extraordinarily concise, operating on entire arrays at once.
dynamic
interpreted
since 1966
arrayfunctionalimperative
APL’s symbol-based notation allows entire algorithms to be expressed in a single line by composing operations over arrays. Developed by Kenneth Iverson, it pioneered array-oriented programming and influenced languages from MATLAB to Julia. Its direct descendants J and K are used extensively in high-frequency trading for their terseness and performance.