Chapter 1. Legacy Applications

In its simplest definition, a legacy application is any application that you, as a developer, inherit from someone else. It was written before you arrived, and you had little or no decision-making authority in how it was built.

However, there is a lot more weight to the word legacy among developers. It carries with it connotations of poorly organized, difficult to maintain and improve, hard to understand, untested or untestable, and a series of similar negatives. The application works as a product in that it provides revenue, but as a program, it is brittle and sensitive to change.

Because this is a book specifically about PHP-based legacy applications, I am going to offer some PHP-specific characteristics that I have ...

Get Modernizing Legacy Applications in PHP now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.