Translation systems can provide the gist of the original text,
however, I wouldn't recommend trying to carry out business
communication or pen pal exchanges using them.
Translation systems can provide the gist of the original text, but still do not provide a natural, complete translation. So, I wouldn't recommend trying to carry out business communication or pen pal exchanges using them. The free options for English/Chinese translation software are also very limited. In most situations, you still need a human.
One page that lists several different translation systems is Chinese Software Digest. Another page in Chinese is at China Computerworld. Other possibilities are EV Dict, Alexander Chinese to English Software, RoboWord English-Chinese Software, TransPerfect, or Systran, but I haven't tried them myself.
If you want a portable translator, try the Besta Handheld Translator.
An on-line English/Chinese automatic translation I know of is the IBM English/Chinese translation engine, where all the instructions are in English. AltaVista's Babelfish also now supports translation to and from Chinese from English. Another possibility is the on-line Gist-in-Time System, which is incorporated into Netscape 6.
English/Chinese MT Software
English to Chinese MT Web Services
Chinese to English MT Web Services
Links of Interest