What is it?
There are more than 200 billion lines of working Cobol code and five billion lines of Cobol are written every year.
Industry analyst Bloor Research said, "This code is not going away because rewriting an application is believed to be five times more expensive than re-using existing applications."
So how do mainframe users reconcile their need to move into the Java and web-enabled future, with the fact that their business systems are founded in a 40-year-old programming language?
Where did it originate?
In 1959 the US Department of Defense convened Codasyl, the Committee on Data Systems Languages, which went on to develop the Common Business Orientated Language.
Intended to be machine-independent - but in practice vulnerable to extensions - Cobol came under the control of the American National Standards Institute and the International Standards Organisation. The most important revisions of Cobol were in 1974, 1985 and 2002.
What is it for?
IBM launched Version 3.3 of Enterprise Cobol in May. It interoperates with Java so that Cobol applications can access chunks of code called Enterprise Java Beans that run on a J2EE-compliant EJB server, such as IBM's Websphere Application Server. Developers can write re-usable EJB in Cobol 3.3 on Websphere z/OS and use them in different environments.
Enterprise Cobol 3.3 also has XML capabilities, meaning Cobol applications can process XML in the most popular mainframe environments, such as Cics, IMS and MQSeries and populate Cobol data structures with the content of XML documents.
What makes it special
Cobol code can be re-used without duplicating it in Java.
Do you need extra skills?
Cobol specialists should take IBM's Websphere Studio Enterprise Developer courses.
Where is it used?
On zSeries mainframes.
What systems does it run on?
IBM also provides Cobol compilers for 0S/390, VSE, AS/400, AIX and Windows. The leading independent Cobol supplier is MicroFocus, with Mainframe Express. Others include Accucorp and LegacyJ.
What is coming up?
Enhanced Cobol interoperability with Enterprise Java Beans, including development tools to allow Cobol programs to be loaded into Websphere Application Server for z/OS operating system.
This was first published in September 2004