POEDIT
Free / Low Cost windows software which can scan your code and then provides all the translation features you need. Seems pretty popular.
WPML
Very popular, very featured, apparently a really good choice its hard to go wrong with and not excessively expensive.
Polylang
Another very popular wordpress choice
Weglot
Different to WPML and Polylang, aimed much more at auto translation of sites and non expert users.
USEFUL?
We benefit hugely from resources on the web so we decided we should try and give back some of our knowledge and resources to the community by opening up many of our company’s internal notes and libraries through mini sites like this. We hope you find the site helpful.
Please feel free to comment if you can add help to this page or point out issues and solutions you have found, but please note that we do not provide support on this site. If you need help with a problem please use one of the many online forums.