Do you have any idea how much COBOL there is in the world? “There are over 220 billion lines of COBOL in existence, a figure which equates to around 80% of the world’s actively used code.” ”200 times more COBOL transactions take place each day than Google searches.” http://blog.codinghorror.com/cobol-everywhere-and-nowhere/
Most companies that have been in business any length of time have lots of software, some of it very old indeed, and a lot of it in COBOL. Any new system is going to have to take the old system into account. Since the old system can be written in not only COBOL, but any of a wide variety of other languages, some of which have almost disappeared from use today, this can present a challenge. It certainly isn’t impossible to have a customer database, a project billing system, and an inventory system, all three dating from different decades and using different hardware. This is a classic enterprise application integration (EAI) issue.
So—how to integrate? Application-interface integration is one solution. Application-interface integration uses the application programming interfaces (APIs) in the legacy system to access the data and the functionality hidden in it. The good news is that there are many packages that use this approach; the bad news is that COBOL banking systems in the 1970s weren’t written with the needs of some futuristic software package in mind, and what they provide in the way of APIs may be difficult to make use of.
Enter legacy wrapping. Legacy transactions are wrapped with callable APIs, providing an access point. It will be interesting to see what new applications are on the horizon to preserve the value of all that old COBOL code while making it as useful (or more useful) than anything written in C, C+, or C#.