  The continuous increase in performance requirements, for both scientific
computation and industry, motivates the need of a powerful computing
infrastructure. The Grid appeared as a solution for inexpensive execution of
heavy applications in a parallel and distributed manner. It allows combining
resources independently of their physical location and architecture to form a
global resource pool available to all grid users. However, grid environments
are highly unstable and unpredictable. Adaptability is a crucial issue in this
context, in order to guarantee an appropriate quality of service to users.
Migration is a technique frequently used for achieving adaptation. The
objective of this report is to survey the problem of strong migration in
heterogeneous environments like the grids', the related implementation issues
and the current solutions.
