Languages
German
Since German is my mother tongue, I have no problems speaking it fluently and understanding difficult texts. Even if English is the lingua franca there are many documents only available in German. Moreover, speaking German is a huge advantage with regards to the mass of German computer scientists, because it might ease communication for both sides when they can talk about difficult topics in their mother tongue. Moreover, I try to help foreign people with learning German. For this purpose I talk with them on German or correct their German exercise texts.
English (C1)
I started to learn English in 2001 (5th grade at school). Constantly using the language in oral and written form has helped to reach fast progress. Due to daily usage I am not limited to the usage of school vocabulary, but can also understand specialised texts about computer science (e.g. programming manuals).
French (B1)
French is one of the most distributed languages in the world. It is spoken in Europe, America and Africa and a common language for documents about programming. Since the French border is not far away, I have learned French in school for five years as of 2003. Yet, French can also be useful with regards to programming. Searching for solutions for difficult solutions, you sometimes find help in French communities, which could not be used without knowledge about the language. Besides, many French people are really interested in the idea of open source.
Japanese (B1)
Being fascinated by both the culture and the language I started to learn Japanese in 2007 on my own. Since Japan has the second highest gross domestic product of the whole world, it is worth knowing the mother tongue of potential business partners. It will always seem much more polite and earnest, if you know a bit more than only a mispronounced 「今日は」 (Good afternoon). Moreover, you should be familiar with the conventions of Japanese people. For example, you should avoid just putting the business card in your pocket without reading it before.
Swedish (A1)
With my one year experience of Danish, I commenced studying Swedish at home in 2010. Swedish is very similar to Danish, but much easier to pronounce and might be more important for me in future.