Guys, I installed Oracle 11g client because of the reported fix of System.Transactions issue known in 10g. I use PL/SQL developer, and it told me "Initialization error: Could not locate OCI dll", though the registry entry and ORAHOME folder it showed were Ok. It seems like PL/SQL developer was looking for OCI.dll not in the reported ORAHOME folder but in ORAHOME\bin folder. After copying all files (luckily, they are quite few) from ORAHOME root to bin PL/SQL developer began to work correctly.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com