"I have discovered that there are two types of command interfaces in the world of computing: good interfaces and user interfaces"
About this Quote
The line lands as a joke with an edge. It points to a habit in software culture where the label "user interface" becomes a euphemism for something glossy, inconsistent, and ultimately hostile to real users. By contrasting "good interfaces" with "user interfaces", Daniel J. Bernstein draws a sharp line between tools that are clear and reliable and tools optimized for demos, novices, or marketing checklists.
Bernstein is a systems programmer and cryptographer known for opinionated, utilitarian software like qmail and djbdns. His world prizes predictability, security, and composability. From that perspective, a good interface is one that exposes clear commands and stable semantics. It is discoverable through concise help and real documentation, it behaves the same way every time, and it fits into larger workflows. A good command takes inputs and flags, emits machine-parseable output, can be scripted and automated, and supports a dry-run to reduce risk. It is not necessarily pretty, but it is dependable.
What he calls "user interfaces" tend to prioritize surface friendliness: wizards, modal dialogs, icons with unclear meanings, state hidden behind tabs, and outputs trapped in pixels rather than text. They discourage reuse and automation, force repetitive pointing and clicking, and make exactness hard. They also drift with each release, breaking muscle memory and scripts alike. Paradoxically, they often serve neither beginners nor experts well, because the veneer of simplicity conceals complexity instead of managing it.
The jab is not about hating GUIs. It is about respecting users enough to give them interfaces that are testable, reversible, and composable. A dialog box with a vague OK button is less humane than a command with explicit flags like --dry-run or --force. A one-off wizard is less humane than a repeatable command captured in a script. Real usability is not about hiding power; it is about shaping power so that intent is clear, consequences are predictable, and work can be reproduced.
Bernstein is a systems programmer and cryptographer known for opinionated, utilitarian software like qmail and djbdns. His world prizes predictability, security, and composability. From that perspective, a good interface is one that exposes clear commands and stable semantics. It is discoverable through concise help and real documentation, it behaves the same way every time, and it fits into larger workflows. A good command takes inputs and flags, emits machine-parseable output, can be scripted and automated, and supports a dry-run to reduce risk. It is not necessarily pretty, but it is dependable.
What he calls "user interfaces" tend to prioritize surface friendliness: wizards, modal dialogs, icons with unclear meanings, state hidden behind tabs, and outputs trapped in pixels rather than text. They discourage reuse and automation, force repetitive pointing and clicking, and make exactness hard. They also drift with each release, breaking muscle memory and scripts alike. Paradoxically, they often serve neither beginners nor experts well, because the veneer of simplicity conceals complexity instead of managing it.
The jab is not about hating GUIs. It is about respecting users enough to give them interfaces that are testable, reversible, and composable. A dialog box with a vague OK button is less humane than a command with explicit flags like --dry-run or --force. A one-off wizard is less humane than a repeatable command captured in a script. Real usability is not about hiding power; it is about shaping power so that intent is clear, consequences are predictable, and work can be reproduced.
Quote Details
| Topic | Coding & Programming |
|---|
More Quotes by Daniel
Add to List
