Yandex cofounder Ilya Segalovich, 48, passed away yesterday in London after suffering from cancer, reports BBC News.

Yandex is Russia’s largest Internet search companies, and one of the biggest tech companies in the entire country — valued at over $10 billion. (And to give you some perspective, Yandex has doubled its market share¬†within Russia itself compared to global search leader Google. )

The company has set up a tribute page for Segalovich with a statement that reads:

Yandex Founder and Director of Technology, author of the first version of the search engine and the words of Yandex, a scholar and a citizen with an active lifestyle, one of the creators of the art rehabilitation center “Children of Mary”, the father of five children.¬†Friend, colleague, teacher, and hilarious clown.

In addition to founding the company, Segalovich helped name Yandex (which is short for Yet Another Index) and served as its chief technology officer.