Difference between Windows and OpenVMS

1. Windows : Windows is a group of various proprietary graphical operating systems which is provided by Microsoft Incorporation. It is also known as Microsoft Windows. It currently includes Windows NT and Windows IoT as members of its family. Earlier it included Windows 9x, Windows Mobile and Windows Phone which are no longer in use. It is the most used operating system in personal computers. The first version of Windows was launched by Microsoft in 1985. It has hybrid kernel with modules. 2. OpenVMS : OpenVMS is a multi-user and multi-processing operating system which was developed by Digital Equipment Corporation (DEC). It is a virtual memory based operating system which is designed for use in time-sharing, batch processing and transaction processing. It is available for many platforms including servers and workstations. It is written using BLISS, VAX Macro, C, Ada, PL/I, Fortran, UIL, Pascal, SDL, C++ and DCL. The first version of OpenVMS was launched in 1977. The kernel used in this operating system is monolithic with modules.
Difference between Windows and OpenVMS :

S.No.	WINDOWS	OPENVMS
1.	It was developed by Microsoft Incorporation.	It was developed by Digital Equipment Corporation (DEC).
2.	It was launched in 1985.	It was launched in 1977.
3.	Its target systems types are workstation, personal computers, media center, tablets and embedded systems.	Its target system types are server and workstation.
4.	Computer architectures supported by Windows are IA-32, x86-64, IA-64, ARM, Alpha, MIPS and PowerPC.	Computer architectures supported by OpenVMS are VAX, Alpha and IA-64.
5.	Its kernel type is Hybrid with modules.	Its kernel type is Monolithic with modules.
6.	Its native APIs are Win32 and NT API.	Its native APIs are Proprietary.
7.	It has the preferred license Proprietary and Source available.	It has the preferred license of Proprietary.
8.	The non-native APIs supported through its subsystems are DOS API, Win16, POSIX and .NET.	The non-native APIs supported through its subsystems are POSIX.
9.	Its package management is MSI or custom installer.	Its package management is PCSI or VMSINSTAL.
10.	It has default GUI 'on'.	It does not have default GUI 'on'.
11.	File systems supported by Windows are NTFS, FAT, ISO 9660, UDF, HFS+, FATX and HFS.	File systems supported by OpenVMS are Files-11, ISO 9660, NFS and CIFS.