APL

APL is A Programming Language with its own special character set combining Greek letters, math symbols, and more. Its characters do not have a Unicode block of their own, but are scattered widely. Here are the APL characters included in Unicode, with their Unicode block names.

A-Z, 0-9, !?()[]',.:/\-_ (ASCII)
¨¯ (Latin-1)
αειρω (Greek)
←↑→↓ (Arrows)
+<=>×÷∆∇∗∘∣∧∨∩∪∼⊂⊃⊢⊣⊤⊥ (Math)
⌶⌷⌸⌹⌺⌻⌼⌽⌾⌿⍀⍁⍂⍃⍄⍅⍆⍈⍉⍊⍋⍌⍎⍏⍐⍑⍒⍓⍔⍕⍖⍗ (Miscellaneous Technical Symbols)
⍘⍙⍚⍛⍜⍝⍞⍟⍠⍡⍢⍣⍤⍥⍦⍧⍨⍩⍪⍫⍬⍭⍮⍯⍰⍱⍲⍶⍷⍸⍹ (Miscellaneous Technical Symbols)
◇ (Block Elements & Geometric Shapes)

A number of APL characters were originally produced by overstriking characters from the base set (originally 88 characters on Selectric typeballs, later extended to 95 in the APL-ASCII overlay mappings). In later APL software, there is support for typing the previously overstruck characters as single characters, typically using the Control or Alt key as a modifier. All APL symbols are included in Unicode, but not in a single block.

The A+ dialect of APL is available in most Linux distributions. It includes its own APL font.

There is no complete standard APL keyboard. Most vendors use either the typewriter-paired or bit-paired overlay layout for the basic symbols, but there is no agreement whatever on the locations of any composite symbols that are provided without overstriking.

APL is a highly mathematical language, which gives it limited appeal in spite of its power. It has been applied to almost everything in computing except writing device drivers, and has been taught in elementary schools.