What makes code legacy?

Question

I have heard many developers refer to code as \"legacy\". Most of the time it is code that has been written by someone who no longer works on the project. What is it that ma

Answer 1

It is a very general (and oft abused term) but any of the following would be legitimate reasons to call an app legacy:

1. The code base is based on a language/platform which is entirely unsupported by the manufacturer of the original product (often said manufacturer has gone out of business).

2. (really 1a) The code base or platform on which it is built is so old that getting qualified or experienced developers for the system is both hard and expensive.

3. The application supports some aspect of the business which is no longer actively grown and for which alterations are extremely rare, normally to fix it if something entirely unexpected changes around it (the canonical example being the Y2K issue) or if some regulation/external pressure forces it. Since both reasons are pressing and normally unavoidable but no significant development has occurred on the project it is likely that those people assigned to deal with this will be unfamiliar with the system (and it's accumulated behaviours and intricacies). In these cases this would often be reason to increase the perceived and planned for risk associated with the project.

4. The system has/or is being replaced with another. As such the system may be used for much less than originally intended, or perhaps only as a means of viewing historical data.