OmegaT+ is on of those cases. OmegaT is a good CAT Tool, but OmegaT+ takes that good application to a further step and oofers the user a very good application with a lot of more options and better performance.
OmegaT+ interface is divided into panel, so we will have on screen the original and the meta text, glossaries, search tools, online dictionaries and even statistics.
OmegaT+ can import and export translation memories, so you can use the ones you created wusing other programs.
If you need a Computer Assisted Translation tool, OmegaT+ is probably the best free choice out there.