I see that Oracle has release Oracle Express 11g for windows 32 bit and Linux 64bit system. You can get it from the link below.
http://www.oracle.com/technetwork/database/express-edition/downloads/index.html
I also saw this interesting article about using Oracle Goldengate to connect to Microsoft SQL Server. I find this of interest due to previous experience using the 'Transaparent Gateway' to get information from SQL Server to Oracle for a client. I enclose the link for those of you that may want to have a look.
http://www.oracle.com/technetwork/articles/datawarehouse/oracle-sqlserver-goldengate-460262.html