Free and open source software is free to use and modify. This is possible because open source provides access to the source code. The software is under continuous modification and improvement by a developer community of dedicated programmers. The breadth of the supporting programmer and user community are indicators of the quality and usefullness of the software. A technical person can generally find answers to questions by web searching. If that fails there are forums for posting questions to the developer and user communities. Non-technical folks can hire contract support.