Hi! I want to use a browser and a download manager with German language support.
Nowadays, most of the applications have support for the most used languages like: English, Spanish, German, Italian and Portuguese. Chrome, Opera, Firefox, Safari, Internet Explorer are the most common and most used browsers on the planet and all of these have support for the German language. Regarding the download managers I can recommend you Internet Download Manager which has a great support for almost all spoken and written languages.