of the GPL required more immediate attention of FSF's licensing staff, and as

such, much of the early 2000's was spent doing GPL enforcement

work\footnote{More on GPL enforcement is discussed in \tutorialpartsplit{a

      Compliance}}{Part~\ref{gpl-compliance-guide} of this tutorial}.}.  In

2006, FSF began in earnest drafting work for GPLv3.

Also, GPLv3~\S2\P2 gives an explicit permission for a client to provide a

copy of its modified software to a contractor exclusively for that contractor

to modify it further, or run it, on behalf of the client.  However, the

changes to the GPL-covered program.  The parts of the program it obtained

from other contributors must be provided to the contractor with the usual GPL

freedoms.  Thus, GPLv3 permits users to convey covered works to contractors