(ref.doc)spe27-3

Software Practice & Experience
March 97, Vol 27, No 3

p 207 Synchronous/Reactive Programming of Concurrent System Software
by B.R. Montague and C.E. McDowell
  We can identify three orthogonal attributes that affect the systems
  programmer:
   1. Competitive vs Cooperative
   2. Heavyweight, lightweight, or featherweight
   3. Internal vs external

   A reactive system is event-driven, maintains a permanent
   interaction with its environment, and executes at a rate determined
   by the environment. [...]
   The term reactive is more specific than the informal term
   event-driven [and] more general than soft real-time and near
   real-time.

   The synchronous hypothesis assumes that all computation occurs in
   discrete atomic steps during which time is ignored [...] The
   fundamental advantage of this approach is that internal cooperative
   concurrency can be handled deterministically.

p 311 A Practical Approach to Object-oriented State Modelling
by Maher Awad and Jürgen Ziegler