Oracle, IBM, Microsoft Three Database Vendors have released their own free database products.
Three free database comparison
Name CPU memory database size 32-bit, 64-bit operation platform Oracle 10g EX1 <= 1 <= 4G32-bit Windows / Linuxibm DB2 Express-C <= 2 <= 4 Do not limit 32 bits and 64-bit Windows / LinuxMicrosoft SQL Server 2005 Express1 < = 1 <= 4G32 bit Windows