Open DBDiff - A database comparison tool for Microsoft SQL Server 2005+ that reports schema differences and...
DBConvert for Oracle & PostgreSQL - Migrate Oracle database to PostgreSQL server or backwards.
Redgate SQL Data Compare - Use Redgate SQL Data Compare to compare and synchronize static, lookup, and reference data in your SQL Server database - try it free
KS DB Merge Tools - Database diff and merge tools
DBComparer - Free Compare database tool - DBComparer 3.0 is a professional compare database tool for comparing Microsoft SQL Server 2008 (and 2005) database structure.
Devart Studio for SQL Server - dbForge Studio for SQL Server is a powerful SQL Server GUI Tool for SQL Server database management, administration, development, datareporting and analysis.