The Finnish philosopher Georg Henrik von Wright was one of Wittgensten's three heirs and literary executors. In the 1960s he created a Wittgenstein archive in connection with his office at the university, which was reopened 2009 as the von Wright and Wittgenstein Archives (WWA) at the University of Helsinki.
The background of WWA

Georg Henrik von Wright (1916–2003) was internationally famous for his work on philosophical logic, philosophy of action, philosophy of science and philosophy of norms and value. He was also well-known for his essays on literary, cultural and social matters, written mostly in his native language, Swedish. von Wright was the first Scandinavian philosopher who was honoured with a volume in the Library of Living Philosophers-series in 1989.

von Wright first met Ludwig Wittgenstein in 1939 as a postgraduate student at Cambridge. The acquaintance was renewed when von Wright returned to Cambridge after the war. In 1948 von Wright succeeded Wittgenstein as Professor of Philosophy at Cambridge. When Wittgenstein died in 1951, von Wright was named one of his three literary executors, together with Elizabeth Anscombe and Rush Rhees. Several books that have been compiled on the basis of Wittgenstein’s Nachlaß, including Über Gewissheit, Zettel, Bemerkungen über die Grundlagen der Psychologie, Prototractatus and Vermischte Bemerkungen, were either edited or co-edited by von Wright.

Since the 1960s von Wright also made extensive research work on the contents of Wittgenstein’s Nachlaß, involving cataloguing and research on the origin and composition of central works like the Tractatus and Philosophische Untersuchungen. von Wright also discovered new items like the manuscript that came to be known as the Prototractatus. In connection with his research work on the Nachlaß von Wright also compiled a complete collection of copies of its different parts, which now forms the main body of the Wittgenstein-half of WWA. The Wittgenstein material and the part of von Wright’s own literary estate that are included in WWA were donated to the University of Helsinki 2000. In addition, von Wright two years later donated the scientific part of his home library together with a large part of his scientific and private correspondence to the Helsinki University Library, nowadays called the National Library of Finland. Administratively separate from WWA, this collection is now known as the The Georg Henrik von Wright Collection.