be combined, then copyleft obligations do not extend to the independent work

separately distributed.  Thus, far from attempting to extend copyleft beyond

the scope of copyright, GPL explicitly limits the scope of copyleft to the

scope of copyright.

GPL does not, however (as is sometimes suggested) distinguish ``dynamic''

from ``static'' linking of program code.  It is occasionally suggested that a

subroutine ``dynamically'' linked to GPL'd code is, by virtue of the linking

alone, inherently outside the scope of copyleft on the main work.  This is a

misunderstanding.  When two software components are joined together to make

one work (whether a main and some library subroutines, two objects with their

respective methods, or a program and a ``plugin'') the combination infringes

the copyright on the components if the combination required copyright

permission from the component copyright holders, as such permission was

either not available or was available on terms that were not observed.

In other words, when combining other software with GPL'd components, the only

available permission is GPL\@.  The combiner must observe and respect the GPL

observed on the combination as a whole.  It matters not if that combination

is made with a linker before distribution of the executable, is made by the

operating system in order to share libraries for execution efficiency at

runtime, or results from runtime references in the language at runtime (as in

Java programs).

\medskip

\label{GPLv2s2-at-no-charge}

The next phrase of note in GPLv2~\S2(b) is ``licensed \ldots at no charge.''

This phrase  confuses many.  The sloppy reader points out this as ``a

contradiction in GPL'' because (in their confused view) that clause of GPLv2~\S2 says that re-distributors cannot

charge for modified versions of GPL'd software, but GPLv2~\S1 says that

they can.  Avoid this confusion: the ``at no charge'' \textbf{does not} prohibit re-distributors from

charging when performing the acts governed by copyright

law,\footnote{Recall that you could by default charge for any acts not

governed by copyright law, because the license controls are confined

by copyright.} but rather that they cannot charge a fee for the

\emph{license itself}.  In other words, redistributors of (modified

and unmodified) GPL'd works may charge any amount they choose for

performing the modifications on contract or the act of transferring

the copy to the customer, but they may not charge a separate licensing

fee for the software.

GPLv2~\S2(b) further states that the software must ``be licensed \ldots to all

third parties.''  This too yields some confusion, and feeds the

misconception mentioned earlier --- that all modified versions must be made

available to the public at large.  However, the text here does not say

that.  Instead, it says that the licensing under terms of the GPL must

extend to anyone who might, through the distribution chain, receive a copy