<li>The most up-to-date nightly build with a JIT, if the official
release is too old for what you want to do.</li>
<li>No JIT: A version without the JIT. Consumes a bit less memory
and may be faster on short-running scripts.</li>
<li>Stackless: Provides <aclass="reference external"href="http://www.stackless.com/">Stackless</a> extensions, as well as <aclass="reference external"href="http://codespeak.net/svn/greenlet/trunk/doc/greenlet.txt">greenlets</a>.