Brownfield

[Ernesto]

Brownfield is a construction term that describes previously developed land. In the IT industry, it refers to previously developed software. Brownfield software development is software that is built from an existing program. It may be contrasted with greenfield development, which involves creating a software program from scratch.
Since the software industry has been around for several decades, the vast majority of software development is brownfield. For example, each new version of Adobe Photoshop and Microsoft Word is developed as a brownfield project. Even modern video games, such as Call of Duty: Black Ops 3 and StarCraft 2, are created from earlier versions of the software.
Brownfield software development has many advantages over greenfield projects. For instance, whenever a software company releases an update to a program, they have a good idea of the market for the software. They also know what features and style of interface their users expect. Adding new features and interface enhancements is less time consuming than developing a program from scratch. Therefore, brownfield development is less costly and involves less risk than greenfield development.

[Becky]

used to refer to an area of land in a town or city that was previously used for industry and where new buildings can be built:

[Merna]

(of an urban site for potential building development) having had previous development on it.