Software Development *Is* Program Transformation

Let's celebrate another post from Ralph Johnson...

I do not say that program development *should* be program transformation, I claim that it already is. Most work on software is after the first released version. The purpose of work on existing software is to transform it to the new version. Since almost all work on software is converting version N to version N+1, almost all work on software is program transformation...

I do not claim that program transformations are easy, or that they can be automated, or even that we can always understand them. I am claiming that thinking of software development as program transformation is likely to lead to improvements in how we develop software.