80column

80column refers to a convention in text formatting and computer display settings that limits the width of a line of text to eighty characters. The practice emerged from early typewriter specifications, where paper widths were capped at roughly eighty characters per line. When computers and terminal emulators became widespread in the 1970s and 1980s, many development environments, operating systems, and source‑code editors adopted the same width as a default setting. The 80‑column limit provided a practical maximum for screen real estate and helped ensure consistent readability across a variety of displays and printed output devices.

The convention is especially prominent in programming. Languages such as C, Java, and Python, and code review guidelines from companies like Google and Microsoft, frequently recommend keeping source‑code lines within 80 columns, often via linting tools or formatting assistants. This standard aids maintainability, as code can be displayed side‑by‑side in web interfaces, version‑control diff tools, or printed on standard paper without wrapping. It also mitigates the risk of horizontal scrolling in older terminals or low‑resolution monitors.

Beyond programming, many terminal users keep their shell prompt and command history within the 80‑column limit to preserve alignment in scripts and batch files. Documentation, literate programming, and early email clients frequently required prints to fit within standard printable paper margins, reinforcing the standard.

In modern multi‑monitor setups and high‑resolution displays, the 80‑column constraint is less strictly enforced, yet it remains a useful guideline in many professional coding standards and remains part of a broader culture of readable, portable text.