BaBar Software Support
                         ====================== 

BaBar software releases [0] are fully supported on a limited number of
platforms [1].  "Fully supported" here means that the releases 

- include binary libraries and executables 
- have been tested on the specified platforms 


The primary requirement for a platform to be included in the supported
list  is that  inclusion produces  a net  gain for the  collaboration,
weighing    the support   load    against the    increased ability  of
collaborators to contribute to the central software effort.  Inclusion
(or re-inclusion)  of  a  platform must  be   approved by  the release
coordinator and the computing  management  and may be dependent   upon
provision of support effort. 

As stated elsewhere [2], by  default  collaborators are granted  write
access to  the  BaBar central  CVS   repository.  To  enable BaBar  to
maintain the   quality    of  software on    supported   systems  some
restrictions must  be imposed  upon  all software  contributed to  the
central CVS repository. By  definition,  code committed to  the central
repository   is  public BaBar   code.  It  is   assumed  that any code
contributed  to this repository is  of  high quality,  has been  fully
tested and is capable of running on all  supported platforms, and will
be supported  by  the author(s).  Promotion   of CVS modules to  BaBar
"Package"s, for inclusion in  software  releases, is performed by  the
release  coordinator.  This promotion  will depend upon the suitability
and stability  of the package (determined  by the  release coordinator
and   computing system management) and  the  appointment of a "package
coordinator" to take responsibility  for the package (including the CVS
module).  Tagged releases of individual packages  MUST be fully tested
on at least two supported platforms. 

 Modifications  to the central software  must also  meet the following
requirements : 

- Modifications to source code must conform to either
  a) the ANSI FORTRAN-77 standard [3]
  b) the subset of the draft ANSI C++ standard which is implemented 
    by the GNU C++ compiler (version defined in [1])
- The restricted (in F77) use of preprocessor directives is allowed 
to enable platform specific details  to be handled.  However, this 
only applies to "supported platforms".
- Due to the significant testing and support burden that they bring, 
modifications to makefiles or other code to enable software to run
on an unsupported system are NOT permitted. 


 The last point  can be taken  as a working  definition of whether or
not your system is   a "supported system".   If you  need to edit  the
makefiles  to  make something   work  on your   own system  (which  is
different from one of the reference platforms) then your system is not
a supported system and you can not commit these changes. 


Collaborators are  free to use BaBar  software  on whichever platforms
they  choose and facilities exist  in the  standard releases to enable
local  requirements/modifications to  be   handled.  (The ability   to
locally configure  the  BaBar software  releases  to use non-supported
systems will itself be a supported feature whereever possible).  Local
modification of  this   nature will not be   included  in  the central
repository (until   such  time as  the system   in  question becomes a
supported system). 


Signed:
Gerry Abrams  Robert Jacobsen  Neil Geddes   Thomas Glanzman 
Frank Porter  David Quarrie    Torre Wenaus


[0] This refers specifically to software managed under the official
BaBar Software Release System (SRT).  Other BaBar code, notably for
the online system, may exist outside this system where there is no
requirement that this code be available on all supported platforms.
Such code should still be managed and made available to the
collaboration via the central CVS repository .

[1] The definition of a "platform" here is taken to mean a combination of 
Underlying hardware 
+ Operating system 
+ Compiler/linker 
+ other required software (gmake, tcl, g++ ...).  

At the time of writing the supported platforms are based on 
HP-UX A.09.03
DEC OSF/1 V3.2A revision 17
AIX 3.2

The reference g++ compiler version is 2.6.3, changing to 2.7.2 shortly.

See the computing Administration web page 
(http://www.slac.stanford.edu/BFROOT/doc/www/CompAdmin.html)
for a full definition of the currently supported platforms and  
details of reference machines to be used for testing purposes.

[2]  BaBar Computing Policy: Access to CVS code repository.
 http://www.slac.stanford.edu/BFROOT/Computing/Admin/codeAccessPolicy

[3] Certain extensions to this standard have been allowed in specific 
cases  to help smooth our transition to OO. These extensions should not
 be generally used.