We are pleased to announce the support of EPSG 5806 in gvSIG CE. This is a cartesian coordinate system used in engineering environments (for example, surveys) as an XY, non-world and unprojected coordinate reference system. We began this task by evaluating the problem  and finally we produced a document with a full analysis as well as the possible solutions .
After some work, we managed to implement a good solution in the short term, minimizing the efforts. We leave the integration of GeoTools as a possible solution in the middle-long term .
This feature will be available in the next gvSIG CE release.
Thank you very much to David Bibby from Landesdenkmalpflege Baden Württemberg for supporting this feature and to Benjamin Ducke for its contribution and further development.
A continuously updated release announcement, detailing the progress on new features and bug fixes can be found here
 Evaluation of how to implement a cartesian coordinate system support (EPSG:5806)
 Cartesian coordinate system support (EPSG:5806)