Today, rolling your own logging package instead of using something like log4j is as silly as trying to build your own web server instead of using Apache httpd was 10 years ago. Still, there are other components like guava that are less well known, but are currently making a name for themselves as libraries that can take the solution you are building to the next level of sophistication and quality. Just knowing they exist—and knowing where they fit—can help you design and build better software at a lower cost.
In addition to conducting a traditional build versus buy analysis, it’s critical to think about the maintenance and support story surrounding an open source package. Here are some things to consider and questions to ponder."