SQL Server database schema (and likely, some data changes) - how to auto-distribute over many database instances
Rather than trying Opensource or free tools, I would highly recommend using Redgate tools for schema comparison. (note: I am not working for or affiliated to Redgate, but have and is using the schema and data compare and trust me they are life saving !)

For sql server : SQL Compare.

Useful resource for automating using Powershell or command line.

for Oracle : Schema Compare for Oracle

Note: Just to mention, there is Data compare to sync data as well.