Copying README.md from release branch.

Author: rouson

README.md

@@ -5,6 +5,7 @@
 # OpenCoarrays #
 
 * [Overview]
+* [Downloads]
 * [Compatibility]
 * [Prerequisites]
 * [Installation]
@@ -18,11 +19,17 @@ OpenCoarrays provides a compiler wrapper (named "caf"), a runtime library (named
 
 OpenCoarrays defines an application binary interface ([ABI]) that translates high-level communication and synchronization requests into low-level calls to a user-specified communication library.  This design decision liberates compiler teams from hardwiring communication-library choice into their compilers and it frees Fortran programmers to express parallel algorithms once and reuse identical CAF source with whichever communication library is most efficient for a given hardware platform.  The communication substrate for OpenCoarrays built with the preferred build system, CMake, is the Message Passing Interface ([MPI]).
 
+OpenCoarrays enables CAF application developers to express parallel algorithms without hardwiring a particular version of a particular communication library or library version into their codes.  Such abstraction makes application code less sensitive to the evolution of the underlying communication libraries and hardware platforms.
+
+<a name="downloads">
+## Downloads</a> ##
+Please see our [Releases] page.
+
 ## <a name="compatibility">Compatibility</a> ##
 The GNU Compiler Collection ([GCC]) Fortran front end ([gfortran]) is OpenCoarrays-aware for release versions 5.1.0 and higher.  Users of other compilers, including earlier versions of gfortran, can access a limited subset of CAF features via the provided [opencoarrays module].  After installation, please execute the "caf" script (which is installed in the "bin" directory of the installation path) with no arguments to see a list of the corresponding limitations.  Please also notify the corresponding compiler vendor and the OpenCoarrays team that you would like for a future version of the compiler to be OpenCoarrays-aware.
 
 ## <a name="prerequisites">Prerequisites</a> ##
-We expect our LIBCAF_MPI library to be the default OpenCoarrays library.  LIBCAF_MPI is the most straightforward to install and use, the most robust in terms of its internal complexity, and the most frequently updated and maintained.  Building LIBCAF_MPI requires prior installation of an MPI implementation.  We recommend [MPICH] generally or, if available, [MVAPICH] for better performance.  [OpenMPI] is another option.
+We expect our LIBCAF_MPI library to be the default OpenCoarrays library.  LIBCAF_MPI is the most straightforward to install and use, the most robust in terms of its internal complexity, and the most frequently updated and maintained.  Building LIBCAF_MPI requires prior installation of an MPI implementation.  We recommend [MPICH] generally or, if available, [MVAPICH] for better performance. [OpenMPI] is another option.
 
 We offer an unsupported LIBCAF_GASNet alternative.  We intend for LIBCAF_GASNet to be an "expert" alternative capable of outperforming MPI for some applications on some platforms.  LIBCAF_GASNet requires greater care to configure and use and building LIBCAF_GASNet requires prior installation of [GASNet].
 
@@ -55,7 +62,7 @@ Please see the [STATUS.md] file.
 ## <a name="acknowledgements">Acknowledgements</a> ##
 We gratefully acknowledge support from the following institutions:
 
-* The National Center for Atmospheric Research [NCAR] for access to the Yellowstone/Caldera supercomputers and for logistics support during the initial development of OpenCoarrays.
+* [National Center for Atmospheric Research] for access to the Yellowstone/Caldera supercomputers and for logistics support during the initial development of OpenCoarrays.
 * [CINECA] for access to Eurora/PLX for the project HyPS- BLAS under the ISCRA grant program for 2014.
 * [Google] for support of a related [Google Summer of Code] 2014 project.
 * The National Energy Research Scientific Computing Center ([NERSC]), which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, for access to the Hopper and Edison supercomputers under the OpenCoarrays project start allocation.
@@ -64,13 +71,14 @@ We gratefully acknowledge support from the following institutions:
 [Hyperlinks]:#
 
 [Overview]: #overview
+[Downloads]: #downloads
 [Compatibility]: #compatibility
 [Prerequisites]: #prerequisites
 [Installation]: #installation
 [Contributing]: #contributing
 [Acknowledgements]: #acknowledgements
 
-[NCAR]: https://ncar.ucar.edu
+
 [OpenCoarrays]: http://www.opencoarrays.org
 [ABI]: https://gcc.gnu.org/onlinedocs/gfortran/Function-ABI-Documentation.html#Function-ABI-Documentation
 [TS 18508]: http://isotc.iso.org/livelink/livelink?func=ll&objId=16769292&objAction=Open
@@ -99,3 +107,4 @@ We gratefully acknowledge support from the following institutions:
 [Google Summer of Code]: https://www.google-melange.com
 [OpenCoarrays Google Group]: https://groups.google.com/forum/#!forum/opencoarrays) 
 [Issues]: https://github.com/sourceryinstitute/opencoarrays/issue
+[Releases]: https://github.com/sourceryinstitute/opencoarrays/releases