In this article I want to give a presentation of CAT (Computer-Aided Translation) tools. If you translate regularly, these tools are great and can save you time and hassle. Of course, some of them are not free, but if you are a professional, they are worth the investment. If you don't feel like paying for them, there are also some free options which support quite a few of the features.

So, what can CAT tools exactly do for you?
Here are the main features:

1. They offer a single-window translation environment. Normally, when translating, you use Word or any other word processor, and you probably have two windows: one with the original text and one with your translation. Switching back and forth can be annoying so this feature spares you the trouble.

2. They use translation memory technology. This matches your translation with the original text as best as it can, and saves these pairs for later use. Every time you encounter one of the previous words or structures, the program offers you translation suggestions.

3. They support tagged and programming-language files. If you need to localize something, the software recognizes the computer language instructions and stops you from translating them, allowing you to focus only on the text to be translated.

Here are three of the most important CAT tools:

1. SDL Trados Studio 2009
OS: Windows
Web site: http://www.translationzone.com/en/products/sdl-trados-freelance/
Price: €755/$945

This is the market leader. It supports the basic features plus many others, so it's a bit complex. Its major drawbacks are that it only works on Windows and that it's quite pricey.

2. Wordfast Pro
OS: Mac, Linux, Windows
Web site: http://www.wordfast.com/products_wordfast_60.html
Price: €300/$485

This is the runner-up. It boasts simplicity of use while still supporting a lot of features, and it's also a lot cheaper than Trados. The low price combined with the multi-platform support makes it a very good choice for many translators.

3. OmegaT
OS: Cross-platform
Web site: http://www.omegat.org/en/omegat.html
Price: Free

OmegaT is a solution proposed by the open-source community. It supports many file formats, including some of the most important ones, and many features found in the commercial programs.

There are many more options to choose from. You can find a list of CAT tools here. Now, start experimenting and find the one suitable for you.
Happy translating.