Silicon Fen (sometimes the Cambridge Cluster) is the name given to the region around Cambridge, which is home to a large cluster of high-tech businesses, especially those related to software, electronics, and biotechnology. Many of these have connections with the University of Cambridge, and the area is now one of the most important technology centres in Europe.
It is called "Silicon Fen" by analogy with Silicon Valley in California and Silicon Glen in the Clyde-Forth region.
In 2004, 24% of all British venture capital, and 9% of all in the European Union, was received by Silicon Fen companies, according to the Cambridge Cluster Report 2004 produced by Library House and Grant Thornton.
The so-called Cambridge phenomenon, giving rise to start-up companies in a town previously only having a little light industry in the electrical sector, is usually dated to the founding of the Cambridge Science Park in 1970: this was an initiative of Trinity College and moved away from a traditional low-development policy for Cambridge.
The characteristic of Cambridge is small companies (as few as three people, in some cases) in sectors such as computer-aided design. Over time the number of companies has grown; it has not proved easy to count them, but recent estimates have placed the number anywhere between 1,000 and 3,500 companies, spread over a broad area in Cambridge itself and beyond. IT companies see a premium in having a "Cambridge" address and ideally telephone code, though the effect has spread as far as Ely, and beyond the county bounds to Newmarket, Saffron Walden, Royston and Huntingdon.
In February 2006, the Judge Business School reported estimates that suggested that at that time, there were around 250 active start-ups directly linked to the University, valued at around US$6 billion. Only a tiny proportion of these companies have so far grown into multinationals: ARM and Autonomy Corporation are examples of those which have done. More recently CSR has seen rapid growth due to the uptake of Bluetooth.
The region has one of the most flexible job markets in the technology sector, and people are often employed by other companies after a start-up fails. Although everyone wants their company to succeed, failures are tolerated, indeed almost expected.
One explanation for the area's success is that after a while such an employment market is self-sustaining, since employees are willing to move to an area that promises a future beyond any one company. Another factor is the high degree of 'networking', enabling people across the region to find partners, jobs, funding, and know-how. Organisations have sprung up to facilitate this process, for example the Cambridge Network.
Cambridge also enjoys the academic pre-eminence of the University of Cambridge, the high standard of living available in the county, good transport links, and a relatively low incidence of social problems.
The high-technology industry has little by way of competition for talent. Because Cambridgeshire was not until recently a high-technology centre, commercial rents were generally lower than in other parts of the United Kingdom, giving companies a head-start on those situated in other more expensive regions; this has, however, been changing.
- The Cambridge Cluster Report 2007, Library House 2007, Download
- The Cambridge Phenomenon: The Growth of High Technology Industry in a University Town, Segal Quince & Partners 1985, ISBN 0-9510202-0-X
- The Cambridge Phenomenon Revisited - a synopsis of the new report by Segal Quince Wicksteed, Segal Quince & Partners 2000, Download
- The Cambridge Cluster Report 2003, Library House 2003, Download
- The Cambridge Cluster Report 2004, Library House in association with Grant Thornton 2004, Download
- The Cambridge Cluster Report 2006, Library House 2006, Download
- The Cambridge Technopole Report 2006 An overview of the UK's leading high tech cluster, St John's Innovation Centre 2006, 
- The Impact of the University of Cambridge on the UK Economy and Society A high-level study commissioned by EEDA and the Cambridge Network in 2006,