Hi, I have started working on a large code base built using drupal 5.2 and now there is a requirement to upgrade it to 5.22 and eventually 6. The problem is that lot of core files (modules, include folder) was hacked over a period of last 1 year to make drupal work according to req, and things were obviously not done drupal way. I am working on identifying changes that were made to core and then would attempt on implementing those changes from a custom module, reverting the core to 5.2 clean state. The job would have been easier if source control management was used from start in the project, but that did not happen and hacks were made before SCM started recording them and hence I can not rely on svn history. What I am doing right now is the following: 1> I have downloaded drupal 5.2 for reference. 2> Have trunk of tainted project checked out. 3> Diffing module files one by one ( against 5.2 download in step 1, so diffing hacked node.module against 5.2 node.module) and recording changes to find out what changes were intended when the developer hacked the core (eg. node module file) For 3 to happen, I can write a script to get diff of all files in say includes folder, but that would give me just the diff file and it would be hard to study why were the changes done. But I am sure I can use it as a starting tool to find out which files have changed in core when measured against cleand drupal 5.2 and then focus on those files. I wanted suggestions and tips on: 1> Apart from svn history, diffing files one by one, does any one have suggestions to find out changes between hacked and clean file? Maybe at a folder level? Like diff the whole include folder or diff the whole modules folder. (I know about beyond compare, anything else?) 2> Any tips, experiences, suggestions on the process of removing core hacks and implementing them outside of core. 3> Any suggestions on the whole approach? If it can be made more efficient. I would like opinion of anyone who has dealt with core hacks and removed them to clear upgrade path. Thanks Dipen