Grandma used to say, "Don't copy, be original". Software engineering says, "Don't reinvent the wheel".
Whom do you trust? Trust software engineering if Grandma was not a software engineer!
They have copied and they have built great things that way. Saying "copying" could be controversial, so based on what is a more politically correct term to describe copying, let's go with inspiration. Thus, to state in diplomatic terms, they have got inspired from an existing software and created a new software altogether.
But, is this evil? What if that software did not exist? What if that software is quite useful?
Putting colors in this black-and-white picture, there was software: a build tool available for another language, Java, with the name Ant. People (the programmers) who were PHP enthusiasts thought of having a similar build tool, so some good people toiled hard and created Phing for the task. Thus, Phing has become a build tool for PHP, and it is said that Phing is Ant-based.
Some PHP...