Why Write Open Source Libraries

I just created my third open-source project on SourceForge, S34J. It's a set of a half-dozen objects that encapsulate the calls for Amazon's Simple Storage Service (S3) — at least, it will be once I finish the code. My other two projects are PracticalXML, a utility library hiding the (often painful) Java XML API, and SwingLib, a library of Swing GUI enhancements that currently has three classes (mostly because I haven't taken the time to upload more).

Other than PracticalXML, I don't expect anyone to ever use these libraries. And for PXML, I don't expect anyone other than the other maintainers, all former coworkers, to use it. So why write them, and why take the time to create a SourceForge project? The answer can be found in the project description for SwingLib:

Classes that I've written for Swing programming. Possibly useful for other people.

Throughout my career, I've written the same code over and over again. Such as a method that creates an XML element that inherits the namespace of its parent. Simple code, a matter of a few minutes to write, but after the third or fourth time it gets annoying. Particularly if you have a several dozen such methods. And once I type that code on an employer's computer, it becomes their property; I can't simply take a copy on to my next job (I'll note here that ideas, such as an API, are not protected by copyright; I always make a DomUtil class, and it always has an appendChildInheritNamespace() method, but the implementation has been from-scratch each time).

An auto mechanic acquires his tools over a lifetime, and takes them from job to job; they don't belong to the shop where he works. By releasing this code as open source, I can do the same. And, who knows, someone else might stumble on it and decide it's useful.