IVOA Recommendation: SAMP - Simple Application Messaging Protocol   Version 1.3
  SAMP is a messaging protocol that enables astronomy software tools to interoperate and communicate.   IVOA members have recognised that building a monolithic tool that attempts to fulfil all the requirements of all users is impractical, and it is a better use of our limited resources to enable individual tools to work together better. One element of this is defining common file formats for the exchange of data between different applications. Another important component is a messaging system that enables the applications to share data and take advantage of each other's functionality. SAMP builds on the success of a prior messaging protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy applications and has proven popular with users and developers. It is also intended to form a framework for more general messaging requirements. 
M. Taylor, T. Boch, M. Fitzpatrick, A. Allan, L. Paioro, J. Taylor, D.   Tody
astro-ph.IM