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Marshall Lochbaum, a former Dyalog APL developer and J contributor, released BQN in 2020 as a from-scratch rethink of the APL family. It is an array language with first-class functions, a carefully chosen set of glyph primitives, and strong support for tacit (point-free) programming, but it drops APL's legacy quirks in favor of consistent, context-free syntax. BQN has built a lively community around the CBQN implementation and shows up regularly in Code Golf Stack Exchange answers and array-programming study groups. On XCODX you can run BQN in a real interactive terminal: the program executes live, so anything read from stdin can be typed while it runs, with no interpreter to install.
# •Out prints one line of text to stdout
•Out "Hello, World!"BQN is a strong pick for array-oriented code golf, where a single train of primitives can replace an explicit loop, and for Code Golf Stack Exchange challenges tagged with array manipulation. It is equally useful as a teaching vehicle: students who know only scalar languages get a concentrated dose of rank, folds, and tacit composition. Puzzle programmers also use it to prototype matrix and combinatorics solutions before porting them elsewhere.
BQN keeps APL's array paradigm and dense glyph vocabulary but redesigns the details: syntax is context-free, functions are first-class values, and the primitive set was chosen fresh rather than inherited. Casing distinguishes roles, so Foo is a function while foo is a subject. The result reads more predictably than classic APL while staying just as expressive for array work.
Yes, within its niche. For array-heavy challenges BQN routinely lands near Jelly and 05AB1E in byte count when scored in its own codepage, because trains and modifiers compress whole algorithms into a few glyphs. It lacks the built-in compression and web-of-shortcuts that purpose-built golfing languages carry, so on string or I/O-centric tasks those usually win.
Locally, BQN users install a keyboard layout or editor plugin that maps glyphs to a backslash prefix, and the online REPL at mlochbaum.github.io offers clickable glyph bars. When working in the XCODX editor you can paste glyphs directly, and copying from BQN documentation or existing golf answers works without any encoding trouble since everything is plain UTF-8.
main.bqnplain text — no highlighter ships for this languageno standard input construct"Hello from BQN!"