Many developers who have used the Google Translate API are not happy that it is now being "deprecated" and will close entirely in December 2011.
The Google Translate API is just one of the many APIs to be closed by Google in the near future but is it one of the most popular. Along with it go the other language oriented APIs - Transliterate, Virtual Keyboard and Diacritize.
The Translate API was deprecated on May 26th and it will close on 1st December 2011. The period of grace is only six months because the API never graduated from Google Labs and so was never a "real" frontline API. Even so many programmers have used it to do clever things.
It is important to stress that the Translate API is not the Google Translate web site, nor the Google Translate Web element - which you can see on this page in the first column. What this means is that users will still be able to use Google to translate text that is copy and pasted into the text box; users of Google Toolbar will still be able to translate whole web pages and any website that embeds the Translate Web element will be able to offer whole page translation to its end users.
What has been swept away is any custom use of the REST-based API that allows you to write applications that submit text to be translated. So, for example, if you wanted to provide a one-time completely translated version of your web site you can't do it any more using Google Translate unless you are prepared to submit blocks of text manually or use some HTML scraping hack.
The announcement on the Google code website doesn't give much of a clue as to why the API is being terminated:
Important: The Google Translate API has been officially deprecated as of May 26, 2011. Due to the substantial economic burden caused by extensive abuse, the number of requests you may make per day will be limited and the API will be shut off completely on December 1, 2011. For website translations, we encourage you to use the Google Translate Element.
What is clear is that the reason is not that there is something intrinsically wrong or not useful about the API - this is an API that is being dropped because of "abuse". Surely the correct response to such a situation is to find a way to make the API resistant to "abuse" and let the programmers who want to use it correctly get on with using it.
It is also clear that a lot of programmers are very annoyed with Google and basically this and many of the other dropped APIs have made many think hard about adopting a Google technology in the future. Google doesn't seem to have a response to this PR disaster.
As they say there are other translation APIs - Bing Translate being an obvious alternative.