Here at GovDesign, we are big fans of open source. We use an open source software package called WordPress to build awesome websites. Open source makes for great software, but there is a lot of misunderstanding about it. GovLoop recently put out a whitepaper on open source software. See their post here, and the PDF here.
The guide includes a survey of government IT professionals. On the value of open source:
Another benefit: Agencies do not have to deal with proprietary vendors and outdated solutions, making the agency more agile. “Open source enables lower cost solutions and innovation,” a respondent said.
In fact, the guide mentions quite a few benefits. The guide is very informative, and education is important with open source software. Go have a read.