Formal definition of term 'legacy'

This is not the kind of term that is going to get a formal definition. It is often a euphemism for "MS-DOS."

or for character-oriented applications whether on mainframe, unix, or msdos

To my mind, the term legacy has nothing to do with Microsoft, Unix or Posix, certainly when dealing with embedded environments. It is purely and simply used to refer to older projects, the creators of which are usually no longer available to reap as they have sown.

Wikipedia defines a legacy system thusly: "A legacy system is an antiquated computer system or application program which continues to be used because the user (typically an organization) does not want to replace or redesign it. " I can't argue too much with that. The term is not judgmental. I've worked on many "legacy" projects in my in my professional life. Some are good; well desinged and documented and easy to migrate to more modern development tools, others are a nightmare.

hth, Alf

As far as most sales and marketing departments are concerned, a "legacy" system is one that exists, and actually does something.

True story: At the beginning of the month, I was at a status meeting for a project we're doing some work on. This has been in development since last fall, is in QA right now for a beta release (hopefully) in the quite near future. A representative from another division proposed replacing the "Legacy Xyz" system. Yes, the one not quite yet in beta!!! In fact he meant that he thought the system under development should be scraped, and development started anew, but he used the term legacy as a synonym for "bad."

Yes, the term "legacy" is not actually pejorative, but is almost always used that way. As far as I'm concerned you should almost always avoid using the term.

You have to rid yourself of the idea that if people abuse a tool (and a word is just that: a tool, used in communication), fixing the tool is going to prevent that. The problem in such case is what people

*think*, not which words they use to express their thoughts.

It's not a technical or engineering term, so a formal definition of it is neither to be expected, nor would it be all that helpful.

But as you insist: the root of the term comes from people dying and leaving more than just goods, but also burdens to their heirs. A legacy is something like "Rule the kingdom in my spirit, son, and do marry that princess of , or our dynasty is sure to falter."

In the life of companies, it means any productive equipment they use whose original makers have since moved on, be that by death, retirement, being fired or any other movement, i.e. for which support is no longer available. Identifying such legacy equipment as a serious problem on the horizon has nothing to do with propaganda; they

*are* serious problems in the long term.

The propaganda only begins where people abuse the term to mean anything they believe old-fashioned.

--
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

The definition is context-specific; in the subdivision where I work, it is used to refer to any equipment based on communication protocols that are not "next-generation".

Hmm, lots of responses suggesting that people use "legacy" to mean stuff that should be abandoned and replaced. However I've almost always seen "legacy" used in a context to mean something that must continue being maintained and supported. Ie, when you upgrade to a new system, the older legacy systems on the network continue to function without having to upgrade everything.

Legacy can be used with software too. Such as "our new RTOS release will continue to work with your legacy code with no changes".

In some sense, "legacy" is the counterpoint to "upstart".

-- Darin Johnson