Get the snapshot archive via FTP from
ftp://sourceware.cygnus.com/pub/libstdc++/You will probably need to use one of the mirror sites due to the heavy load on the main server.
The master CVS repository for libstdc++-v3 is now a part of the gcc repository. As such, checking out the gcc module includes the current libstdc++-v3 development sources. To check out libstdc++-v3 only, use libstdc++-v3 instead of gcc as the module.
You can also browse the CVS repository over the web.