These are BOSCO tarballs for several platforms.
They are the stripped tarballs from the 8.6.4 release.
They were built in the NMI lab from the head of 
the V8_6_4-branch (207225e866dfd5b).
The NMI run id 408625
boscoinstaller is a copy of bosco_findplatform in the source tree.
bosco_quickstart is copied out of the source tree.