The article discusses open source software, which is software that is freely made
available to users with the intention of allowing the programming community to collaboratively
improve it. It is also about free software, which is software that can be used
without paying, but the users cannot make any changes in it. The article describes how
those two types of software can be useful in academic libraries. Librarians believe that
open source software and free software can be a huge help for them. This article
presents results of research made in academic libraries in Lodz (Poland).