| History | COE concept | DII COE-supported operating systems |
| DII COE-Q & A Forum - an Email discussion Group |

The Defense Information Infrastructure Common Operating Environment (DII COE) provides a foundation for building open systems. It is a "plug and play" open architecture designed around a client/server model. The DII COE model is analogous to the Microsoft Windowsr paradigm. It provides a standard environment, a set of standard off-the-shelf components, and a set of programming standards that describe how to add new functionality to the environment. The DII COE is designed to run on PCs and workstations; it extends the Windows paradigm, which allows applications to coexist, by providing the capability for mission applications to share data and services/functions at the server level. Thus, the DII COE allows for true integration of open systems. This article provides an introduction to the DII COE. It includes background on the COE; information on currently available versions of the COE; and instructions for ordering a copy; as well as pointers to the wealth of resources available to software developers who are interested in using the COE. History The DII COE concept originated in the early to mid 1990s with a simple observation about the Department of Defense's (DOD's) command and control (C2) systems: Certain functions (mapping, track management, communications interfaces, etc.) are so fundamental that they are required for virtually every C2 systems. In "old" DOD software development environments, developers were building these common functions from scratch for every system. Each developer implemented the functions differently, which led to incompatibility between the systems. Thus, while most of the production systems used by the DOD had similar functions, they could not easily interoperate with each other. Also, the DOD was investing a great deal of time and money in rebuilding the same functions. In planning for building the replacement for one of the most critical C2 systems, the World-Wide Military Command and Control System (WWMCCS), the DOD evaluated several architectures with the goal of selecting a system architecture that would be able to easily take advantage of emerging commercial products and standards. The Global Command and Control System (GCCS), which has replaced the WWMCCS, is built upon an open architecture that both meets the DOD's unique functional needs (the GCCS systems architecture) and provides for interoperabilty with other systems (the GCCS COE technical architecture). The open/technical architecture developed for GCCS provided the baseline for the DII COE. Longer term development of the COE is being managed by the Defense Information Systems Agency's Joint Interoperability and Engineering Organization (DISA/JIEO); development is being driven by the requirements of major efforts such as: GCCS; Command, Control, Computers, Communications and Intelligence (C4I) for the Warrior; logistics support systems for the DOD's Global Combat Support System (GCSS), and financial support systems for electronic commerce/electronic data interchange (EC/EDI). COE concept The DII COE concept encompasses the following: an architecture and approach for building interoperable systems; an infrastructure for supporting mission area applications; a rigorous definition of the runtime execution environment; a rigorous set of requirements for achieving COE compliance; an automated toolset for enforcing COE principles and measuring COE compliance; an automated process for software integration; a collection of implemented, reusable software components; an approach and methodology for software reuse; a collection of application program interfaces (APIs) for accessing COE components. Figure 1 provides a view of the DII COE and the relationship to COE-based systems. The shaded box illustrates the two types of reusable software that the applications may access through APIs: COE components and the operating system. DII COE-supported operating systems The DII COE is being designed to be hardware independent; it will operate on a range of operating systems running under standards-based systems. DISA is developing DII COE implementations based on user requirements. Currently, DISA has developed versions of the COE for Windows NT 3.5.1 and 4.0, and for a variety of flavors of Unix, including Solaris and HP. Also, beta versions are available for IBM AIX and Digital Unix. To obtain your copy of the COE, see the sidebar at the right. DII COE Q & A Forum -- an E-Mail Discussion Group for DII COE Issues The DII COE listserv provides a moderated forum for COE developers. Messages are sent and received through the user's ordinary e-mail service. For those who do not wish to subscribe to the listserv, messages may be viewed through an organized archive on the CSEIC Web site at: http://sw-eng.falls-church.va.us/cseic/listserv/maillist.html To subscribe to the DII COE Listserv, send a message to: listproc@sw-eng.falls-church.va.us In the body of the message, write: subscribe diicoe