The osrm.backend package downloads and installs the following third-party software:

1. OSRM Backend (Open Source Routing Machine)
   - Source: https://github.com/Project-OSRM/osrm-backend
   - License: BSD 2-Clause License
   - Copyright (c) 2016, Project OSRM contributors

2. Intel Threading Building Blocks (oneTBB)
   - Source: https://github.com/uxlfoundation/oneTBB
   - License: Apache License 2.0
   - Copyright (c) Intel Corporation

3. BZip2 for Windows
   - Source: https://github.com/philr/bzip2-windows
   - License: BSD-like (bzip2 license)
   - Copyright (c) 1996-2010 Julian R Seward

This package (osrm.backend) does not contain these binaries in its source distribution; 
they are downloaded only upon user request via osrm_install() or osrm_start().