A new SCons checkpoint release, 2.0.0.alpha.20100508, is now available.
  The primary purpose of this release is to remove support for
  Python versions prior to 2.4 and streamline the SCons code base
  using more modern python idioms.
  The checkpoint is available at the SCons download page:

          http://www.scons.org/download.php

  A SCons "checkpoint release" is intended to provide early access to
  new features so they can be tested in the field before being released
  for adoption by other software distributions.

  Note that a checkpoint release is developed using the same test-driven
  development methdology as all SCons releases.  Existing SCons
  functionality should all work as it does in previous releases (except
  for any changes identified in the release notes) and early adopters
  should be able to use a checkpoint release safely for production work
  with existing SConscript files.  If not, it represents not only a bug
  in SCons but also a hole in the regression test suite, and we want to
  hear about it.

  New features may be more lightly tested than in past releases,
  especially as concerns their interaction with all of the other
  functionality in SCons.  We are especially interested in hearing bug
  reports about new functionality.

  We do not recommend that downstream distributions (Debian, Fedora,
  etc.) package a checkpoint release, mainly to avoid confusing the
  "public" release numbering with the long checkpoint release names.

  Here is a summary of the changes since 1.3:

  NEW FUNCTIONALITY

  - There should be no new functionality or bug fixes in this checkpoint.
    Bug fixes will be found in the 1.3.1 series of checkpoints.

  DEPRECATED FUNCTIONALITY

  - All features or usages deprecated in 1.3 should have been removed.
    Uses of formerly-deprecated features should get an error.

  CHANGED/ENHANCED EXISTING FUNCTIONALITY

  - Any Command() or env.Command() calls that use the following Action
    factory functions will have their targets rebuilt when upgrading
    from any pre-2.0 release:

        Chmod()
        Copy()
        Delete()
        Mkdir()
        Move()
        Touch()

    (The rebuild occurs because the underlying Python class that
    implements these functions has been changed to a new-style Python
    class, and that changes the Python byte code and therefore the
    build signature of the functions.)

  FIXES

  - None.

  IMPROVEMENTS

  - Support for Python versions prior to 2.4 has been removed.  As of
    this writing, we belive that SCons will still work with Python 2.3,
    but this is not guaranteed.
  - Code paths that included special cases for older Python versions have
    been streamlined.
  - The code base has been converted to use more modern idioms.  Although
    we don't have any direct measurements (yet), we believe that SCons
    startup time should be decreased and the overall code should run faster.

  PACKAGING

  - No changes.

  DOCUMENTATION

  - No changes.

  DEVELOPMENT

  - Code no longer has to be compatible with Python versions back to 1.5.2.

  Thanks to Greg Noel and Steven Knight for their contributions to this
  release.