Human68k is an operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 for Sharp Corporation

Sharp Corporation

is a Japanese multinational corporation that designs and manufactures electronic products. Headquartered in Abeno-ku, Osaka, Japan, Sharp employs more than 55,580 people worldwide as of June 2011. The company was founded in September 1912 and takes its name from one of its founder's first...

's personal workstation X68000. It's developed by SHARP and Hudson Soft

Hudson Soft

, formally known as , is a majority-owned subsidiary of Konami Corporation is a Japanese electronic entertainment publisher headquartered in the Midtown Tower in Tokyo Midtown, Akasaka, Minato, Tokyo, Japan, with an additional office in the Hudson Building in Sapporo. It was founded on May 18, 1973...

.

Appearance and usage

Generally, it looks like Microsoft

Microsoft

Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

's MS-DOS

MS-DOS

MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...

, but doesn't have IO.SYS

IO.SYS

IO.SYS is an essential part of MS-DOS and Windows 9x. It contains the default MS-DOS device drivers and the DOS initialization program.- Boot sequence :...

 and MSDOS.SYS

MSDOS.SYS

MSDOS.SYS an important system file on MS-DOS and Windows 9x systems. It is run after IO.SYS. In MS-DOS, it contains the core operating system code, the kernel...

. This is because Human68K doesn't care about porting to other hardware platform at all. Hardware-dependent things are done by X68000's IOCS.

The file extension of executable programs is ".X". The command line shell

Shell (computing)

A shell is a piece of software that provides an interface for users of an operating system which provides access to the services of a kernel. However, the term is also applied very loosely to applications and may include any software that is "built around" a particular component, such as web...

 can be started by executing COMMAND.X.
Lately, COMMAND.R was developed as a free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

, and it was relocatable.