| Company | Timeline | Status | |
Amphio Associates Limited Director • Chief Executive | 8 Oct 2010←9 Months→22 Jul 2011 | Dissolved | |
| Wolfram Research Europe Limited Director • Chief Executive | 26 Jan 1992←34 Years→Current | Active | |
| Wolfram Research Europe Limited Director • Unreported | 1 Jan 1970←56 Years→Current | Active | |
