system - Which Mathematica files may be deleted to save space

After installation Mathematica 8 for Linux takes more than 3GB in the /usr/local/Wolfram/ directory. I suspect that not all of it is relevant if I want to do some occasional computations. Are there subdirectories which can be deleted safely to save some space?

Answer

1. 
   

   You can save a lot of space in the Documentation directory by using Delete All Output on all the larger ones and by using disk compression. For example, the v7 documentation Notebook for ContourPlot is 27.7MB, but after deleting output it is only 192k, and after NTFS compression only 72k. Doing this will require evaluating the documentation page before you can see the examples, but it will easily save 500MB for version 7; probably more in later versions.

   
   

   You can modify this answer as per your needs to programmatically delete all the output cells from the notebooks in the Documentation directory.

   
   


2. 
   

   As Oleksandr suggests you can delete the SystemFiles/Java/<$SystemID> folder(s), which contain copies of the JVM, if you have Java installed separately, saving about 190MB of space. (Or, following point #3, about half that.)

   
   


3. 
   

   Initial testing indicates that core functionality is retained after deleting binaries for the other system type (32 or 64 bit) from SystemFiles\Kernel\Binaries, SystemFiles\FrontEnd\Binaries and SystemFiles\Converters\Binaries saving about 88MB for version 7.

   
   

Under Windows you can use WinDirStat to easily visualize the space allocation within a drive or directory tree. That page recommends KDirStat for Linux and Disk Inventory X for OS X.