What is the Japanese Language Stack Exchange called in Japanese? I came up with 日本語のスタック交換.
In technical documents or technical news media, the name of a foreign website or company is typically written completely as-is.
- 日本語についての質問サイトであるJapanese Language Stack Exchange
Mass media for general public (e.g., 読売新聞) usually katakanize foreign proper nouns because many of their readers do not understand English at all:
You should not "translate" foreign proper nouns. Even in English, Mont Blanc is Mont Blanc and Rio de Janeiro is Rio de Janeiro. You should not "translate" them into White Mountain or River of January. Likewise, since Stack Exchange is the name of a website, you must not convert it to スタック交換.
EDIT: An ordinary noun with a literal meaning can be translated, such as 大学 ("University"), 協会 ("Association"), 基金 ("Fund"), 国際 ("International"). A brand name should not be translated even if it has a meaning as a common noun (Apple, Windows, Android, Office, Fox, Seven Eleven, ...). As @Yosh said, partially-translated 日本語スタックエクスチェンジ may also be acceptable in newspapers.