What is the best free (or trial) Oracle database development environment I can have?
Especially I would like to have my databases, or as much as possible of them, locally.
Its Oracle 10, I develop .NET (on Windows), I already have Toad and the free Virtualbox image (Linux) that Oracle provides (But would prefer to have the tools in Windows).
You can download fully functional versions of almost any of Oracle's products from OTN (the Oracle Technology Network). You can download either the full enterprise edition database under the OTN license (which is free for learning/ prototyping purposes) or you can download the express edition of the database which is free to deploy and use in production but is limited in terms of how much RAM it can use, how many CPUs it can use, and how big the database can grow.