some netCDF FAQ answers describing what shared libraries are...

[Ed Hartnett]

Howdy all!

Firstly, thanks to all on this list for all the help getting my
package converted to libtool. The next version of netCDF, a freeware
Earth science software library will build libtool libraries.

There are many users of netCDF around the world, and they are
atmospheric scientists, but not computer scientists. Many have no
understanding of shared libraries and whether they might be useful.

For this reason I have prepared some brief documentation of what a
shared library is, and how it should be used. For those who enjoy
finding fault (and don't we all, secretly ;-) you could tell me the
more obvious mistakes and stupidities from:

http://www.unidata.ucar.edu/software/netcdf/docs/faq.html#Shared%20Libraries

It starts like this:

What are shared libraries?

Shared libraries are libraries which can be shared by multiple running
applications at the same time. This improves performance.

For example, if I have a library which provides function foo(), and I
have two applications which call foo(), then with a shared library,
only one copy of the foo() function will be loaded into RAM, and both
programs will use it. With static libraries, each application would
have it's own copy of the foo() functions.

More information on shared libraries can be found at the following
external sites:

    * The Program-Library HowTo, by David Wheeler.
    * Wikipedia Library Entry


-- 
Ed Hartnett  -- address@hidden