The first release candidates for the 1.90.0 Beta 1 release are now available at: <https://archives.boost.io/beta/1.90.0.beta1/source/> The SHA256 checksums are as follows: 0f55a646eaed4daf110eeec7c2c70e2c7058efa77eef31137248a6e2cf1412da boost_1_90_0_b1_rc1.tar.gz c94235eb00edc732253d3ae8000a489ffc5773f34cd98bd7645d54cb4ae2482a boost_1_90_0_b1_rc1.7z 8072831c2c54c7e0e99c69e934b5694574565dd435de19a0a43f7bf7dabad71b boost_1_90_0_b1_rc1.zip d1754f544e83418c2b5fe18245666830088948cb3629d2b346d56f31c71138e5 boost_1_90_0_b1_rc1.tar.bz2 As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release managers