Symblicity is a 'low-level' esoteric programming language with five 8-bit registers, 512 bytes of directly accessible memory, a double-ended stack, bidirectional execution, direction-sensitive letter jumps, and optional asynchronous audio.

Every non-formatting character in a .sym file has a meaning. Newline, carriage-return, form-feed, and vertical-tab characters are ignored as formatting. A literal TAB begins a comment and ignores the rest of that physical source line. A literal ASCII space is an instruction that skips the next instruction.