There's a difference between (1) online-only translation systems and (2) installable software. Online systems cannot be trained on your own data, so they might not work on your domain. There is also a problem with privacy, if you have to translate sensitive material. Installable software doesn't have these problems, but you have to first install and often train it yourself.
For online-only translations, Google Translate is the state of the art. Microsoft also has one (Bing translate) that's pretty good. But their translation team seems much smaller than Google's.
Note: The Google and Microsoft systems will probably never be available as free downloadable software. But vice versa, it would be cool if someone provided online access to installed and properly trained versions of Joshua, Cedec and Moses. They are all free software, so someone just has to set it up. All of these systems are constantly being developed, so it would be best if the system authors themselves did it.