1. AIX：
AIX是IBM提供的一系列专有操作系统。 AIX代表Advanced Interactive eXecutive。最初，它是为IBM RT PC RISC工作站设计的，后来又用于各种硬件平台，例如IBM RS / 6000系列，基于PowerPC的系统，System-370大型机，PS-2个人计算机和Apple Network Server。它是五个具有The Open Group的UNIX 03标准认证的商业操作系统之一。 AIX的第一个版本于1986年发布。AIX的最新稳定版本是7.2。
2. OpenVMS：
OpenVMS是由Digital Equipment Corporation(DEC)开发的多用户和多处理操作系统。它是一个基于虚拟内存的操作系统，旨在用于分时，批处理和事务处理。它可用于许多平台，包括服务器和工作站。它是使用BLISS，VAX Macro，C，Ada，PL / I，Fortran，UIL，Pascal，SDL，C++和DCL编写的。 OpenVMS的第一个版本于1977年发布。此操作系统中使用的内核与模块是整体的。
AIX和OpenVMS之间的区别：
| AIX | OpenVMS |
|---|---|
| It was developed and is owned by IBM. | It was developed by Digital Equipment Corporation (DEC). |
| It was launched in 1986. | It was launched in 1977. |
| Its target system type is Server, NAS and workstation. | Its target system types are server and workstation. |
| Computer architectures supported are POWER, PowerPC-AS, PowerPC and Power ISA. | Computer architectures supported by OpenVMS are VAX, Alpha and IA-64. |
| Kernel type is Monolithic with modules. | Its kernel type is Monolithic with modules. |
| The native APIs are SysV/POSIX. | Its native APIs are Proprietary. |
| Preferred license is Proprietary. | It has the preferred license of Proprietary. |
| It has default GUI ‘on’. | It does not have default GUI ‘on’. |
| The non-native APIs supported through its subsystems are DOS API. | The non-native APIs supported through its subsystems are POSIX. |
| File systems supported are JFS, JFS2, ISO 9660, UDF, NFS, SMBFS and GPFS. | File systems supported by OpenVMS are Files-11, ISO 9660, NFS and CIFS. |