Many developers I know have some sort of side project. Most of us contribute to an open source project, work on building an idea we have, or have clients for which we write code. Some companies are against this practice, while others simply turn a blind eye. Forward thinking companies, though, actively encourage developers to have a side project.

Side projects are more than just a way to pick up beer money. In some cases, as in contributing to an open-source project, there is no money involved at all. Regardless of the incentive to work on them, side projects can potentially add value for the developer’s main employer in two very important ways.

First, they stretch the developers in new directions, adding new tools to their skill set and sharpening the ones they have. Side projects are not usually related to a developer’s day job—in most cases, contracts actually prevent them from working on things in the same space as their employer. This means that side projects expose developer to new problems and new solutions, some of which can be re-used when they get back to their regular work.

Second, side projects are usually not deadline-driven. Contributing to an Open Source project is voluntary and, as such, most projects respect the fact that, for the most part, they cannot set hard deadlines and demand people to meet them. This freedom from time constraints, not usually enjoyed on projects at work, gives developers time to explore and time to fail. The chance to fail, in particular, is important for developers: software development has been described as “The science of running down alleys till you finds one that isn’t a dead end.” Many companies don’t like it when developers spend a day or two trying a solution that eventually turns out not to work. Side projects allow developers the freedom to do this and the knowledge they learn usually comes back to play in their day job.

If you manage a team of developers, make sure they know they can work on side projects. Review your company’s procedures to make sure that it is clear what the guidelines are. Regularly visit your developers and talk to them about their side projects. Don’t pry, but show an interest. Make sure that they know it’s OK to share with you and the team things that they learn. Make sure your developers aren’t the only one profiting from their side projects.