@cindex license of FGSL
@cindex GNU General Public License
The Fortran interface to the GNU Scientific Library (GSL) provides
access to a large subset of routines of that Applications Programming
Interface. The source code is distributed under the GNU
General Public License.

@menu
* Accessing the GSL API from Fortran::   
* FGSL is Free Software::        
* Obtaining FGSL::               
* No Warranty::                 
* Reporting Bugs::              
* Conventions used in this manual::  
@end menu

@node Accessing the GSL API from Fortran
@section Accessing the GSL API from Fortran

With the advent of standardized C interoperability in Fortran 2003, it has
now become possible to implement portable interfaces to C APIs with 
modest effort. To maintain consistency of usage, many Fortran 90 features
are of course also required, such as the module concept and abstract data types.
Areas of functionality which are already covered by Fortran language functionality
(e.g., arrays, complex types, intrinsic functions) typically are not
implemented in the FGSL; the same applies for interfaces which are already
available as well-established stand-alone packages (e.g., BLAS, LAPACK).

@noindent
Installation and use of the Fortran interface is described in this manual. 


@node FGSL is Free Software
@section FGSL is Free Software
@cindex free software, explanation of
The subroutines in the FGSL are ``free software'';
this means that everyone is free to use them, and to redistribute them
in other free programs.  The library is not in the public domain; it is
copyrighted and there are conditions on its distribution.  These
conditions are designed to permit everything that a good cooperating
citizen would want to do.  What is not allowed is to try to prevent
others from further sharing any version of the software that they might
get from you.

Specifically, we want to make sure that you have the right to share
copies of programs that you are given which use the FGSL, 
that you receive their source code or else can get it if you
want it, that you can change these programs or use pieces of them in new
free programs, and that you know you can do these things.

To make sure that everyone has such rights, we have to forbid you to
deprive anyone else of these rights.  For example, if you distribute
copies of any code which uses the FGSL, you must give
the recipients all the rights that you have received.  You must make
sure that they, too, receive or can get the source code, both to the
library and the code which uses it.  And you must tell them their
rights.  This means that the library should not be redistributed in
proprietary programs.

Also, for our own protection, we must make certain that everyone finds
out that there is no warranty for the FGSL.  If these
programs are modified by someone else and passed on, we want their
recipients to know that what they have is not what we distributed, so
that any problems introduced by others will not reflect on our
reputation.

The precise conditions for the distribution of software related to the
FGSL are found in the GNU General Public License
(@pxref{GNU General Public License}).  Further information about this
license is available from the GNU Project webpage @cite{Frequently Asked
Questions about the GNU GPL},

@itemize @asis
@item 
@uref{http://www.gnu.org/copyleft/gpl-faq.html}
@end itemize

@noindent
The Free Software Foundation also operates a license consulting
service for commercial users (contact details available from
@uref{http://www.fsf.org/}).

@node Obtaining FGSL
@section Obtaining FGSL
@cindex obtaining FGSL
@cindex downloading FGSL
The source code for the library can be obtained by downloading it
from the internet. The URL is
@itemize @asis
@item 
@uref{http://www.lrz-muenchen.de/services/software/mathematik/gsl/fortran/}
@end itemize


@node  No Warranty
@section No Warranty
@cindex warranty (none)
The software described in this manual has no warranty, it is provided
``as is''.  It is your responsibility to validate the behavior of the
routines and their accuracy using the source code provided, or to
purchase support and warranties from commercial redistributors.  Consult
the GNU General Public license for further details (@pxref{GNU General
Public License}).

@node  Reporting Bugs
@section Reporting Bugs
@cindex reporting bugs in FGSL
@cindex bugs, how to report

Bug reports can be filed to @email{bader@@lrz.de}. All bug reports should include:

@itemize @bullet
@item
The edition number of FGSL
@item
The hardware and operating system
@item
The compiler used, including version number and compilation options
@item
A description of the bug behavior
@item
A short program which exercises the bug
@end itemize

Any errors or omissions in this manual can also be reported to the
same address.

@node Conventions used in this manual
@section Conventions used in this manual
@cindex conventions, used in manual
@cindex examples, conventions used in
@cindex shell prompt
@cindex @code{$}, shell prompt
This manual contains examples which can be typed at the keyboard.
A command entered at the terminal is shown like this,

@example
$ @i{command}
@end example

@noindent
@cindex dollar sign @code{$}, shell prompt
The first character on the line is the terminal prompt, and should not
be typed.  The dollar sign @samp{$} is used as the standard prompt in
this manual, although some systems may use a different character.

The examples assume the use of the GNU operating system.  There may be
minor differences in the output on other systems.  The commands for
setting environment variables use the Bourne shell syntax of the
standard GNU shell (@code{bash}).


