
Ranking: 38
Worth: £226m (343m)
Industry: Computers
Interactive educational software netted McDonagh, 55, a former Dublin teacher, £50m early last year when he sold his 30% of Riverdeep, an e-learning company aimed at the American market. He owns 37% of ThirdForce, the Dublin e-learning company, and the reinvested US proceeds should make £167m. He has other assets.
Ranking: 21
Worth: £304m
Industry: Computers