Alfresco allows uploading newer versions of documents in the repository and also keeps track of the version history, it seems. However, I could not find any way to compare or diff a document with its prior versions.
Is this possible? are there any good external plugins or tools for this?
I assume you think of something similiar to the good old Unix diff tool which basically compares text files and can show the result in a human readable form.
The general equivalent situation in alfresco is far more complicated. You have an arbitrary amount of properties of different type. The text file you might think of just happens to have character bytes in cm:content.
So to answer your question : I don't know of any extension providing a general diff between versions, but it should not be two hard rolling your own for text files other simple special comparisons. In the former case you might want to have a look at Java library for free-text diff for libraries providing the base functionality.
Looking for the same functionality and found this Alfresco addon
http://code.google.com/p/versions-difference-alfresco-plug-in/
