“There are literally dozens of open source licenses, and new
combinations and permutations of terms and conditions seem to
emerge with every new open source initiative. Nevertheless, the
Free Software Foundation’s General Public License (GPL) remains the
center of the open source licensing universe. But even the FSF
acknowledges that one license may not be perfect for all
situations. Thus was born the Lesser General Public License (LGPL.)
Far from deserving its name, SourceForge.net lists over 300
projects being developed under the auspices of the LGPL, and
OpenOffice.org has incorporated it as well. The GPL’s “lesser”
cousin certainly gets around.”
“The selling point of the LGPL is that it is an open source
license that enforces sharing between the original and subsequent
developers, but it does not require derivative works to be equally
open. Any changes made to an LGPL program must be repatriated,
but the resulting code may be embedded in software licensed under
any circumstances–even a closed-source commercial license–without
penalty or reprisal. While the LGPL backs down from the political
stance that “all software should be free,” it enables open source
code to be used where the GPL’s viral qualities would be
unwelcome.”
“The poster child of the LGPL (and to a large extent its reason
for being) is the GNU C library that lies at the heart of the gcc
compiler suite and is a core resource in Linux. Putting the library
under the terms of the GPL would have restricted its use to fellow
GPL-licensed programs, which seemed an unreasonable restriction for
a compiler system seeking to gain acceptance and widespread use. As
Richard Stallman explains in his GNU Project manifesto, “[T]o make
our C library available only to free software would not have given
free software any advantage–it would only have discouraged use of
our library.”