Free Open Source is playing an increasing role in the IT industry, Gartner is considering that it is here to last and will represent 10% of IT portfolio in 2010. Free Open Source Software has a lot to offer to single employees as well as to the whole company. A vast variety of software, ranging from small libraries and tools to big frameworks and stand-alone applications, is available without charge and mostly at instant speed. It has been tested by hundreds or thousands of developers, but change requests and bug reports can still be addressed to the community, which commits a new version sometimes a few days later. But there also exists FOSS that has not been tested enough, does not run in a stable mode, or provides far less features than corresponding commercial software. When considering using FOSS inside products, technical and legal problems and uncertainties exist, as well as problems with quality. Business Models have to be adjusted as well, to make better use of FOSS. This document provides a state of the art of FOSS usage by industry and reports about the experiences and problems encountered.