33. Viglen - £61.8m

Like its arch-rival two places above it, the St Albans system builder swallowed a revenue hit but increased profitability during FY11. About £5.5m was eradicated from the top line during the year, but operating profit increased more than threefold to almost £1.8m. The company claims to have increased its focus on storage, high-performance computing and other higher-margin services during the year.