These are BOSCO tarballs for several platforms.
They are the stripped tarballs from the 8.5.4 release.
They were built in the NMI lab from the head of 
V8_5_4_1-branch (920a9164d6c634c).
The NMI run id was 365871
boscoinstaller is a copy of bosco_findplatform in the source tree.
bosck_quickstart is copied out of the source tree.