Since this weekend the latest Oracle Database 19c (19.3) are also available for Windows (64-bit) and Linux on System z.
The Installation sources can be found under https://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html
The Windows (64-bit) version can be found under the following link under Oracle Technology Network https://www.oracle.com/technetwork/database/enterprise-edition/downloads/oracle19c-windows-5539283.html
The zLinux version can be found under the following link under Oracle Technology Network https://www.oracle.com/technetwork/database/enterprise-edition/downloads/oracle19c-linux-zseries64-193000-5539116.html
Happy download :-)