A *(security) *(term) describing a way of controlling access dynamically in a _(computing system) by treating access to _(object)s as provided by a "key" instead of via an "ID Card" (_(user rights)). This is generally more principled, since each object is required to access functionality individually on a lease-per-object basis, while still being able to transfer the use of those leases to other objects during the lease's term.

<ul class="links">
<li>_("What is a Capability, Anyway?"|http://www.eros-os.org/essays/capintro.html).</li>
<li>_("Essays on Capabilities and Security"|http://www.eros-os.org/essays/00Essays.html) on _(EROS) web site.</li>
<li>Norman Hardy's _("site"|http://cap-lore.com/) devoted to capability theory, notably:
  <ul>
    <li>_("A GUI for a Capability System"|http://cap-lore.com/CapTheory/Personal.html)</li>
    <li>_("Capabilities in disguise"|http://cap-lore.com/CapTheory/discip.html)</li>
  </ul>
<li>_("The SPEEDOS Project"|http://www.informatik.uni-ulm.de/rs/projekte/SPEEDOS/) a software-engineering toolkit based on capabilities and confinement.</li>
<li>_("Mark S. Miller Home Page"|http://www.caplet.com/index.html), in particular his _("Agoric Open Systems Papers"|http://www.agorics.com/Library/agoricpapers.html) (see also _(Security) and _(E), a programming language built with capabilities in mind).</li>
<li>Don't miss this article by _("Jonathan Rees"|http://mumble.net/jar/): _(W7, a security kernel based on the Lambda Calculus|ftp://publications.ai.mit.edu/ai-publications/1500-1999/AIM-1564.ps.Z), that <em>could</em> have been called "_(Lambda|Lambda VM), the ultimate capability".</li>
<li><!-- Message-ID: <51d67993.0401080116.675c1224@posting.google.com> -->
In this _("thread"|http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&safe=off&threadm=51d67993.0401080116.675c1224%40posting.google.com&rnum=1&prev=/groups%3Fq%3Dg:thl3257787964d%26dq%3D%26hl%3Den%26lr%3D%26ie%3DUTF-8%26safe%3Doff%26selm%3D51d67993.0401080116.675c1224%2540posting.google.com) on <em>comp.lang.misc</em> _(Peter Van Roy) compares <em>name values</em> in _(Oz) with <em>capabilities</em> and then concludes:
<blockquote>
You're right, name values are a kind of capability too! They only have one operation, though: equality comparison.
</blockquote>
</li>
</ul>
