I read this Gawker article about how a writer reused some of his older material for new assignments for different magazines.

Is there any similar ethical (societal?) dilemma when doing the same thing in the realm of Programming? Does reusing a shared library you've accumulated over the years amount to self-plagarizm?

What I'm getting at is that it seems that the creative world of software development isn't as stringent regarding self-plagarism as say journalism or blogging. In fact on one of my interviews at GS I was asked what kind of libraries I've developed over the years, implying that me getting the job would entail co-licensing helpful portions of code to that company.

Are there any cases where although it's legal to self-plagarize, it would be frowned upon in the software world?