protobuf-java:
using 2.5.0 right now
https://code.google.com/p/protobuf/
New BSD License

guava:
using 16.0.1 right now
https://code.google.com/p/guava-libraries/
Apache License 2.0

joda-time:
using 2.3 right now
(maybe: drop this before initial release)
http://www.joda.org/joda-time/
Apache License 2.0

jsr305:
using latest, as of 2014-05-07, used for source code annotations
https://code.google.com/p/jsr-305/
New BSD License


for testing:
junit:
using 4.11 right now
http://junit.org/
Eclipse Public License Version 1.0 

truth:
using 0.16 right now
http://truth0.github.io/
Apache License 2.0

hamcrest:
using 1.3 right now
https://code.google.com/p/hamcrest/
New BSD License

