Daum Search is the search function of Daum, a South Korean web portal. Users search web documents, images, videos, blogs, books and Korean online communities (cafes). The search is also available to developers through a Kakao API. It is delivered as a web service focused on Korean-language content and is not open source.
Daum merged with Kakao, the company behind KakaoTalk, in 2014, and according to Kakao's developer documentation the search service is operated by Kakao Corp. That is a South Korean company, so it is based outside the EU. Kakao states in its privacy policy that it complies with the EU GDPR and describes rights for users in EU countries. The data centres named in that policy are at Korean locations. For European organisations it is mainly a source of Korean search results. Data processing falls under South Korean rules, which matters for European staff who would use it as a general search engine.