Currently autobuild.xml has multiple versions of each configuration. The open source/vcexpress versions can be consolidated into a single set using the msbuild command instead of devenv. However this will require changes to be made in other places, i.e. autobuild_environment_source.py, as devenv is used in them. This will in turn require build-cmd.sh for the 3p-* libs to be altered to make use of the updated autobuild_environment_source.py. We could also use these changes to abstract some configuration to the autobuild.xml (as arguemnts/options for build-cmd.sh) of those libs (platform, toolset, etc) which would allow for more flexibility and choice for the future; e.g. 64-bit builds.