OmegaT is a free translation memory tool written in Java so it runs on Windows, Linux and Mac platforms. If the project is handled by a capable project manager translators can use this tool without any problems. However, in the real world you might have to solve the issues yourself. Nevertheless, it is a good program that does what it is supposed do very nicely. Now since my first use of OmegaT it has changed and improved a lot and it is now possible to choose between paragraph or sentence segmentation. Earlier versions suffered from by only offering paragraph segmentation. I think you should try OmegaT...