I think that, as such, your question is a wee bit narrow and not specifically related to academia. There is, however, a deeper related question which I believe is worth answering:
What language services are worth considering for research articles, for non-native speakers (or native speakers with subpar writing skills)?
This is the question I will try to answer below.
- Translation software or online services: under no circumstances.
- Spellchecking software: good to catch typos, pluralization errors, and the like. Worthless for any other use.
- Grammar checking software: grammar checking modules of nonspecialized software (say, MS Word) is useless. Specialized software is little less than useless, and typically fails to grasp the more complicated sentence structures that are somewhat typical of academic writing.
- Thesaurus: now that's a useful tool. One of the limitations of non-native speaker is that even if our vocabulary is quite broad, we typically have a much more restricted “active” lexicon (that which we use spontaneously). Thus, our language often sounds dull or unvaried. A thesaurus is a good tool to make you say “yeah, I could have thought of using ‘monotonous’ instead of ‘unvaried’”. To me personally, this is one of the most precious tools.
- Real-life or online discussion fora: of course, our sister site English Language & Usage comes to mind here. Also, remember that you can also ask advice from native speaker friends or colleagues… that invited professor whom you showed the town around on his first week-end will probably be happy to give you a helping hand over coffee on a particular paragraph you have trouble with.
- Proofreader or other comprehensive language service: sometime necessary. If you feel your English level is preventing you from getting the recognition your work deserves, this is a good money investment in the short term.
- Translater: to be avoided unless your English is really, really poor. Technical translators who really understand your field will be very hard to find, unless you have colleagues who would like to moonlight :) Non-technical translators are to be avoided, as their translations are very unreliable.
The bold items above correspond to the combination of tools I use myself. Note that I consider my own level of English to be quite decent for a non-native speaker… whether it is an excess of self-esteem you can judge for yourself ;-)