A propretary *(collection-oriented) *(programming language) descendent of _(APL).

From its home page:
<blockquote>
J is a modern, array oriented, high level, high performance, general purpose _(programming language). J is used in a variety of industries including banking, investment analysis, insurance, derivative trading, scientific research, and education.
</blockquote>

<ul class="links">
  <li>_("Jsoftware home page"|http://www.jsoftware.com/).</li>
  <li>_("Juggle home page"|http://juggle.gaertner.de/), J for _(Unix).</li>
</ul>
