For example, for English choose - Bing Translator [Auto]->English en-GB (bing.com) by strel
To translate selected text, you then select that search engine by clicking the searchbar favicon, selecting that Bing Translate one, paste the text into the searchbar and hit the magnifying glass icon there and it's done. Same site does hundreds for Google Translate as well.
SeaMonkey also has its own built-in translate function under Tools > Translate Page, which is a Google translation.
None of the above is quite as convenient as what the Chrome-like browsers offers, as I recall. However, to offer that, Google is looking over your shoulder on every single page you visit!