Then there is Archivas (recently acquired by Hitachi Data Systems) and Caringo. Q: What accounts for the difference in yield between compression and file deduplication?

The main difference is where the values are stored. A SAS data file is a type of SAS data set that contains both descriptor information about the data and the data values themselves. SAS data views ...

I could easily see the differences between two versions of the same HTML file, and merge them any way I wanted to. Beyond Compare also has a feature for finding differences between image files.