== Previous NEMOVAR code organization ==
The current repository structure (called trunk in figure 2.1) is divided into two main folders: nemo and 
nemovar. The source code of nemovar folder is divided into two other folders: tam (for tangent and adjoint 
module) and inner (for assimilation and test module engines). The re-organization of the code aims at 
achieving a mirror-like between nemo and nemovar source code. For instance, we do not realise easily 
that the current nemovar code is only dealing with the ocean component OPA. In addition, althought the 
final goal of the project is to implement 4DVar assimilation, the tangent and the adjoint modules could be 
used for other purposes. Thus, to prepare further development and follow the flexibility spirit of the NEMO 
platform, it is appropriate to separate what is specific to 4DVar assimilation from what is not.