DUE TO SPAM, SIGN-UP IS DISABLED. Goto Selfserve wiki signup and request an account.
The SDO Java Source Code can be found in the Apache svn repository.
The code for the SDO API is housed in this repository at http://svn.apache.org/repos/asf/incubator/tuscany/java/spec/sdo-api/
The code for the current implementation can be found at http://svn.apache.org/repos/asf/incubator/tuscany/java/sdo/
Source code for previous releases can be found at http://svn.apache.org/repos/asf/incubator/tuscany/tags/java/sdo/