The beta releases are available at: http://boost.cowic.de/rc/ They are identical to the rc2 releases. The files (and associated md5s) are: e3a51b82894a67ac438eaa08192929eb *boost_1_51_0_beta1.tar.gz 1c541236f98dcaa706e7f8eabb11ebfc *boost_1_51_0_beta1.tar.bz2 964f150ce9d7bcaba74255aba73d338a *boost_1_51_0_beta1.zip e23467c3369a53189300c76e8c848aa1 *boost_1_51_0_beta1.7z The final release is scheduled for Monday, August 20th. The release candidate is scheduled to to be built Thursday, August 16th. That gives us less than two weeks to apply post-beta bug fixes and doc updates. Until August 13th permission is not required to merge bug fixes and documentation updates. Starting August 13th permission of a release manager is required for all merges. As always, New libraries and new features are not allowed during a post-beta period. Thanks, -- The Release Managers