The Z-OptimiZr Native Optimization feature for old MS Office files enables to significantly reduce the size of Microsoft Office DOC, PPT and XLS files. The average volume reduction ratios obtained on these files are most often around 50%.

 
"Native" means that the optimized Microsoft Office files remain fully standard Microsoft Office files.
For instance an optimized DOC file remains a fully standard DOC file, an optimized PPT file remains a fully standard PPT file etc.
Thus, these optimized Microsoft Office files can be opened directly in Microsoft Office as well as in any application able to open old Microsoft Office files since there is no need for any 'decompression' of the optimized files.

 
The Native Optimization for old MS Office Files feature requires Microsoft Office to be installed on the computer.