Wabi-Sabi

  From an engineering or design point of view, wabi may be interpreted as the imperfect quality of any object, due to inevitable limitations in design and construction/manufacture especially with respect to unpredictable or changing usage conditions; in this instance, sabi could be interpreted as the aspect of imperfect reliability, or the limited mortality of any object, hence the phonological and etymological connection with the Japanese word sabi (錆, "to rust") (lit., "to rust").

But I prefer to take a more positive view of it. I think any single purpose CLI tool could exemplify the sort of austere asthetic that wabi promotes. Graceful degradation of its functions over time or inputs would be the sabi side of it.