I am just back from 12th NATIONAL CONVENTION ON KNOWLEDGE, LIBRARY AND INFORMATION NETWORKING (NACLIN 2009) of DELNET. There, I argued that Open Source Software is best candidate for being used in Libraries. Both Library as well as Open Source Communities have similar ideologies. Computing history has shown us that both hardware and software have very short life span. They tend to get obsolete in no time when compared to Libraries - which are long term entities. Open Source software is a community effort. Thus there would be someone from community to take place of original developers in case they leave the project. Using Open Source Software is as good as legally owning it. Even libraries can sponsor further development. Thus it is worth to use and adopt open source software for long-term gains and continuity.