Restore a mongo DB from a compose.io backup?

mongodb restore compose-db

The .ns .0 .1 etc. files are the data files themselves.

This the raw db you can mongodump those files and then mongorestore as always:

This solution would work pre mongo 3.0, but --dbpath is no longer supported by mongodump.

Mongo 3.0 Solution:

Run mongod --dbpath ./ from the directory with the extracted download with the .ns files.
Run mongodump -d [DBNAME] -o [DIR TO DUMP TO] ...options are not required.
Proceed with a mongorestore as normal