d while all the background R processes are busy executing,
then the new future will be queued until one of the background processes
free up.</li>
<li><code>multicore</code>: Each new task executes in its own forked
child process. Forking is generally much faster than launching a new
process from scratch, and most of the state of the original process is
available to the child process without having to go through any extra
effort (see the section about Globals below). The biggest limitation of
forking is that