The Linux Filesystem Hierarchy Standard publication on the web address which directories are shareable. Most software is installed in the /usr directory and
http://www.pathname.com/fhs/
excerpt:
Historical UNIX-like filesystem hierarchies contained both static and variable files under both /usr and /etc. In order to realize the advantages mentioned above, the /var hierarchy was created and all variable files were transferred from /usr to /var. Consequently /usr can now be mounted read-only (if it is a separate filesystem). Variable files have been transferred from /etc to /var over a longer period as technology has permitted.
Here is an example of a FHS-compliant system. (Other FHS-compliant layouts are possible.)
[code]
shareable unshareable
---------------------------------------------------------------------
static /usr /etc
/opt /boot
---------------------------------------------------------------------
variable /var/mail /var/run
/var/spool/news /var/lock
/code]
Sharing partitions this way will also make backups easier. Shared partition only need to be backed up on one server.
Short of sharing these directories, many programs can be used using the client/server model, such as the Open Office suite, the font server, the latex server, etc.
There is a book that deals with centralized automated administration on linux 'Automating UNIX and Linux Administration' by Kirk Bauer.
Good Luck!
