Does stSoftware make available the full source code under an escrow agreement?
stSoftware has a practice of releasing ALL source code to the client.
Every system release includes ALL the source code required to build the system. The libraries that the system is built on are all open source mostly Apache Licence, BSD or LGPL ( not GPL or Affero GPL)
http://en.wikipedia.org/wiki/Comparison_of_free_and_open-source_software_licenses