Håkon Wium Lie (born 1965 in Norway) is, as of 2006, Chief Technology Officer of Opera Software, where he has worked since 1999.

He attended Østfold College, West Georgia College and MIT Media Lab receiving an MS in Visual Studies in 1991. On February 17th, 2006 he successfully defended his PhD thesis at University of Oslo.

He is best known for proposing the concept of Cascading Style Sheets in 1994. He has worked for, among others, the W3C, INRIA, CERN, the MIT Media Lab and Norwegian telecom research in Televerket.

In 2005 he proposed the Acid2 test which was later developed and published by the Web Standards Project.

In 2005 he joined the board of YesLogic, the company that makes the Prince XML + CSS formatter.

Bibliography

Lie has, along with Bert Bos, written a book on CSS, now in its third edition.

Cascading Style Sheets: Designing for the Web, ISBN 020141998X

Cascading Style Sheets: Designing for the Web (2nd Edition), ISBN 0201596253

Cascading Style Sheets: Designing for the Web (3rd Edition), ISBN 0321193121