This is a directory of translation software rather than a review of it. Commercial machine translation systems are badly documented compared with the research literature: vendors disappear, product names are reused, and marketing claims outlive the software. The catalogue below records what each system was, in the terms its own documentation used.

What counts for this directory of translation software

Three categories, kept separate because they were sold to different buyers. Institutional systems ran on mainframes for governments and large firms and were priced accordingly. Desktop packages arrived with the personal computer and sold for a few hundred dollars. Free web services arrived in 1997 and changed the expectation permanently.