The fact that you can host your own translation memory is very significant if you are running a large organization doing translation, or crowdsourcing.

I work for a nonprofit is using the WWL API to manage a collaborative translation effort — http://meedan.net. We think WWL is really important. In particular, this part: http://www.worldwidelexicon.org/api

If you are already invested in translating your content, the WWL API really saves effort — it gives you a machine-translated baseline for your translators, from the translation services of your choice. Your translators are all available over an API, which can talk to a server that you own. This is different from the Google Translation Toolkit, in that it can use any translation API (eg, Yahoo) and you can do whatever you want with the translation metadata.

The Firefox Toolbar is especially cool seen in this context, since it makes the system usable with no setup, and an Open Source backend.

Here is an O’Reilly Radar review:
http://radar.oreilly.com/2009/08/world-wide-lexicon-toolbar-cha.html

“Brian McConnell’s latest coding effort, World Wide Lexicon Toolbar, meets my criterion for a piece of critical infrastructure: after two days with it I can’t get along without it, and I plan to avoid any browser that doesn’t have it installed.”