EDIT: These steps were specifically for 5.3, but I would expect something similar for D6 (and up) since there is still a DFC installer. The primary trick is to get the DFC to work with eclipse.
This is a pretty esoteric post and is largely for my own memory.
1. Add to your .bashrc and .profile:
DOCUMENTUM_SHARED=/ThePathYouWantToUse/Documentum/share; export DOCUMENTUM_SHARED
DOCUMENTUM=/ThePathYouWantToUse/Documentum; export DOCUMENTUM
LD_LIBRARY_PATH=/ThePathYouWantToUse /Documentum/share/dfc; export LD_LIBRARY_PATH
2. Then you can install the DFC (only the first two are required by the installer, but you’ll need the 3rd to execute anything)
3. Install the following (fixes an unsatisfied link error in the libdmcl40.so):
sudo apt-get install gcc-3.3-base libstdc++5
4. You might need to fiddle with other things like the CLASSPATH if you want to run anything from the command line. These steps allowed me to get the JUnit tests to execute from Eclipse.
You can use the JARs to write the code, but to actually run anything, you need the native libraries for Linux (the .so files). The installer works fine on Linux, and you can change the setting of DOCUMENTUM_SHARED and DOCUMENTUM in a shell to get different versions installed in different locations.